[(1,3-dioxo-1,3-propanediyl)diimino)]bisbenzoic acid derivatives

ABSTRACT

Compounds of the general formula: ##STR1## wherein A and B are both hydrogen, or one of A and B is a group (G) of the formula: ##STR2##  and the other is a group R 5  wherein R 1  is an aryl group or a heterocyclic group, both of them being optionally substituted, and R 4  and R 5  are both hydrogen or together form a single chemical bond, 
     R 2  and R 2  &#39; are independently hydrogen, halogen, nitro, lower alkyl or lower alkoxy, and 
     R 3  and R 3  &#39; are independently carboxy or its functional derivative, with the proviso that (a) when A and B are both hydrogen, then R 2  and R 2  &#39; cannot be both hydrogen, 
     and, where applicable, pharmaceuticably acceptable salts thereof are hyaluronidase inhibitors, and useful as anti-allergic agent and anti-ulcerous agent. Among the compound (I&#39;), those wherein when one of A and B is the group (G) and the other is the group R 5  wherein R 4  and R 5  together form a single chemical bond, R 1  is unsubstituted aryl and R 2  and R 2  &#39; are both hydrogen, then R 3  and R 3  &#39; are independently carboxy or its functional derivative other than methyl ester, are novel.

BACKGROUND OF THE INVENTION

1. Filed of the Invention

The present invention relates to [(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid derivatives which have hyaluronidase-inhibiting, anti-allergic, immunomodulating and anti-ulcerous activities, process for preparation thereof and pharmaceutical composition comprising the said derivative.

It is well known that hyaluronidase is present in various parts of living organism normally in an inactive form and act as a phlogovenic enzyme at the inflammatory site. For example, hyaluronidase has an important role in induction of I (immediate) type allergic reaction and hence the use of hyaluronidase-inhibiting drug in these pathologic conditions appears reasonable.

On the other hand, the conventional antiallergic agents such as chlorpheniramine maleate, disodium cromoglicate, tranilast etc. have a number of deficiencies such as induction of undesirable side effect, insufficiency of peroral absorption, unsatisfactoriness of therapeutic effect and so on. Also, there has been a continuous demand for the anti-ulcerous agent which has a mechanism action of approaching the causal treatment. The inventors have succeeded in developing a anti-allergic and anti-ulcerous agent which has an excellent anti-hyaluronidase activity, on the basis of a conception that hyaluronidase inhibitor is useful as a causal treatment of pathologic conditions such as a allergic disease.

2. Related Disclosures

Japanese Patent Publication (Unexamined) No. 7716/1981 discloses 2,2'-[(1, omega-dioxo-1, omega-alkane (C₁₋₁₀)diyl)diimino]bisbenzoic acid as a cerebral vasospasmodic inhibitor. Japanese Patent Publication (Unexamined) No. 13660/1983 discloses [(1,3-dioxo-1,3propanediyl)diimino]bisbenzoic acid as an azo dyestuff. Australian Journal of Chemistry 36 (1983) 1133-1140 discloses dimethyl 2,2'-[(1,3-dioxo-2-phenylmethylene-1, 3-propanediyl)diimino]bisbenzoate as an intermediate for metal-complexing agent. This dimethyl ester was prepared by a method in which phenylmethylene malonic dichloride was reacted with methyl anthranilate. The said method, however, is disadvantageous and cannot be actually carried out in the commercial production. Further, 2,2'-[(1,3-dioxo-2-aryl- methylene-1,3-propanediyl)diimino]bisbenzoic acid is published by T. Satoh, H. Kakegawa, Y. Momoi, H. Matsumoto,J. Yoshinaga and J. Riku, the inventors, at VIIIth International Symposium on Medicinal Chemistry, Held in Sweden on August 27-31, 1984.

SUMMARY OF INVENTION

In one aspect, the present invention relates to a compound of the general formula: ##STR3## wherein A and B are both hydrogen, or one of A and B is a group (G) of the formula: ##STR4## and the other is a group R⁵ wherein R¹ is an aryl group or a heterocyclic group, both of them being optionally substituted, and R⁴ and R⁵ are both hydrogen or together form a single chemical bond,

R² and Rhu 2' are independently hydrogen, halogen, nitro, lower alkyl or lower alkoxy, and R³ and R^(3') are independently carboxy or its functional derivative, with the proviso that

(a) when A and B are both hydrogen, then R² and R^(2') cannot be both hydrogen, and

(b) when one of A and B is the group G and the other is the group R⁵ wherein R⁴ and R⁵ together form a single chemical bond, R¹ is unsubstituted aryl and R² and R^(2') are both hydrogen, then R³ and R^(3') are independently carboxy or its functional derivative other than methyl ester,

and, where applicable, pharmaceutically acceptable salts thereof.

The compound (I) of the present invention can be prepared by the following proceses.

(a) Group R^(3a) and R^(3'a) in a compound of the general formula: ##STR5## wherein R^(3a) and R^(3a') are independently functional derivative of carboxy, and A, B, R² and R^(2') are as defined above, is converted into carboxy group to give a compound of the general formula: ##STR6## wherein A, B, R² and R^(2') are as defined above, or (b) A compound of the general formula: ##STR7## wherein R², R^(2'), R³ and R^(3') are so defined above, or a metal salt thereof is reacted with a compound of the general formula:

    R.sup.1 --CHO                                              (II)

wherein R¹ is as defined above, to give a compound of the general formula: ##STR8## wherein R¹, R², R^(2') , R³ and R^(3') are as defined above, or

(c) A compound of the general formula: ##STR9## wherein R¹, R², R^(2'), R³ and R^(3') are as defined above, is reduced to give a compound of the general formula: ##STR10## wherein R¹, R², R^(2'), R³ and R^(3') are as defined above, or

(d) A compound of the general formula: ##STR11## wherein A and B are as defined above, or a reactive derivative at the carboxy groups thereof is reacted with a compound of the general formula: ##STR12## wherein R² and R³ are as defined above, and a compound of the general formula: ##STR13## wherein R^(2') and R^(3') are as defined above, or reactive derivatives at the amino groups in these compounds to give a compound of the general formula: ##STR14## wherein A, B, R², R^(2') , R³ and R^(3') are as defined above, or

(e) A compound of the general formula: ##STR15## wherein A, B, R², and R^(2') are as defined above, is esterified to give a compound of the general formula: ##STR16## wherein R^(3b) and R^(3b') are indpendently esterified carboxy, and A, B, R² and R^(2') are as defined above, or

(f) A compound of the general formula: ##STR17## wherein R^(1a) is aryl substituted with hydroxy, and R², R^(2'), R³, R^(3'), R⁴ and R⁵ are as defined above, is lower-alkylated to give a compound of the general formula: ##STR18## wherein R^(1b) is aryl substituted with lower alkoxy, and R², R^(2'), R³, R⁴ and R⁵ are as defined above, or

(g) A compound of the general formula: ##STR19## wherein R^(1c) is pyrrolyl or indolyl, and R², R^(2'), R³, R^(3'), R⁴ and R⁵ are as defined above, is lower-alkylated to give a compound of the general formula: ##STR20## wherein R^(1d) is N-lower alkyl pyrrolyl or N-lower alkyl indolyl, and R², R^(2'), R³, R^(3'), R⁴ and R⁵ are as defined above.

In another aspect, the present invention relates to a pharmaceutical composition comprising as an active ingredient a compound of the general formula: ##STR21## wherein A and B are both hydrogen, or one of A and B is a group (G) of the formula: ##STR22## and the other is a group R⁵ wherein R¹ is an aryl group or a heterocyclic group, both of them being optionally substituted, and R⁴ and R⁵ are both hydrogen or together form a single chemical bond,

R² and R^(2') are independently hydrogen, halogen, nitro, lower alkyl or lower alkoxy, and

R³ and R^(3') are independently carboxy or its functional derivative, with the proviso that (a) when A and B are both hydrogen, then R² and R^(2') cannot be both hydrogen, in association with a pharmaceutically acceptable carrier, diluent or excipient.

Among the compound (I'), the compound of the general formula: ##STR23## wherein the group --COOCH₃ is located at any one of ortho, meta and para position to the group --CONH--, can be prepared by the following processes.

(i) A compound of the general formula: ##STR24## or a reactive derivative at the carboxy groups thereof is reacted with a methylating agent, or

(ii) A compound of the general formula: ##STR25## or a metal salt thereof is reacted with benzaldehyde.

Among compounds which can be used for the starting materials in the present invention, compounds represented by formula (V) infra are novel and can be prepared by the following processes.

(A) A compound of the general formula: ##STR26## wherein R¹, R² and R^(2') are as defined above, is subjected to dehydrating reaction to give compound (V).

(B) A compound of the general formula: ##STR27## wherein R² and R^(2') are as defined above, is reacted with a compound of the general formula:

    R.sup.1 --CHO

wherein R¹ is as defined above, to give the compound (V).

In further aspect, the present invention relates to the pharmaceutical composition comprising as an active ingredient a compound of the general formula: ##STR28## wherein R¹ is an aryl group or a heterocyclic group, both of them being optionally substituted

R² and R^(2') are independently hydrogen, halogen, nitro, lower alkyl or lower alkoxy,

with a pharmaceutically acceptable carrier, diluent or excipient.

DETAILED DESCRIPTION OF THE INVENTION

The terms and definitions described in this specification are illustrated as follows.

When both A and B are hydrogen, the formulae (I) and (I') represent the formula: ##STR29##

When one of A and B is the group ##STR30## and the other is the group R⁵, the formulae (I) and (I') represent the formula: ##STR31##

When R⁴ and R⁵ together form a single chemical bond, the formula (I") represents the formula: ##STR32## and when R⁴ and R⁵ are both hydrogen, the formula (I") represents the formula: ##STR33##

One group of the compound (I) is a compound of the formula: ##STR34## wherein R is a residue derived from an alcohol having two or more carbon atoms by removing hydroxy group.

The term "lower" is used to intend a group having 1 to 6 carbon atoms, unless otherwise specified.

The term "aryl" for R¹, R^(1a) and R^(1b) may include monocyclic aryl such as phenyl, tolyl, xylyl, cumenyl etc. and bicyclic aryl such as biphenylyl, naphtyl etc., preferably monocyclic aryl and naphthyl. The said aryl may optionally be substituted by one or more groups, preferably from one to three groups, selected from the group consisting of halogen such as fluorine, chlorine, bromine and iodine; hydroxy; lower alkoxy such as methoxy, ethoxy, propoxy, isopropoxy etc.; lower alkylenedioxy such as methylendioxy, ethylenedioxy; halo(lower)alkyl such as trifluoromethyl, 2-chloroethyl; cyano; nitro; amino; mono-or di-(lower) alkylamino such as methylamino, ethylamino, dimethylamino; and acylamino, preferably lower alkanamido or lower alkoxycarbonylamino, such as acetamido, benzamido, methoxycarbonylamino etc.

The term "heteroxyclic group" for R¹ may include, for example, 5-membered monocyclic heterocyclic group containing 1 to 4 heteroatoms selected from oxygen, nitrogen and sulfur, such as furyl, thienyl, pyrrolyl, imidazolyl, thiazolyl, tetrazolyl etc.; 6-membered monocylic heterocyclic group containing 1 or 2 heteroatoms selected from oxygen, nitrogen and sulfur, such as pyridyl, piperidyl, piperadinyl, morpholinyl, thiomorpholinyl etc.; 7-membered monocyclic heterocyclic group such as azepinyl, diazepinyl etc.; and condensed heterocyclic group which is consisted of the monocyclic heterocycle as stated above and benzene nucleus condensed with each other, such as indolyl, indazolyl etc., preferably furyl, thienyl, pyrrolyl, pyridyl and indolyl. The said heterocyclic group may optionally, be substituted by one or more groups, preferably from one to three groups selected from lower alkyl such as methyl, ethyl, propyl, isopropyl etc. as well as halogen, hydroxy, lower alkoxy, lower alkylenedioxy, halo(lower)alkyl, cyano, nitro, amino, mono- or di-(lower) alkylamino and acylamino as stated above. The free bond of the heterocyclic group may be attached at any one of the possible positions.

When both R⁴ and R⁵ are hydrogen, the compound (I) represents the compound of the general formula (Ie), and when R⁴ and R⁵ together represent single bond, the compound (I) represents the compound of the formula (Id).

The term "halogen" for R² and R^(2') may include fluorine, chlorine, bromine and iodine.

The term "lower alkyl" for R² and R^(2') may include methyl, ethyl, propyl, isopropyl, butyl, isobutyl etc.

The term "lower alkoxy" for R² and R^(2') may include groups formed by combining lower alkyl groups as stated above with oxygen.

The term "functional derivative" of carboxy for R³, R^(3'), R^(3a), R^(3a') may include esters and amides which are used for protection of carboxy group, as well as a compound of the general formula: ##STR35## wherein R² and R^(2') are as defined above. Examples of the esters may include aliphatic esters, for example, lower alkyl ester such as methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, tert-butyl ester, pentyl ester, 1-cyclopropylethyl ester etc., lower alkenyl ester such as vinyl ester, allyl ester etc., lower lkynyl ester such as ethynyl ester, propynyl ester etc., lower alkoxy(lower)alkyl ester such as methyoxymethyl ester, 1-methyoxyethyl ester etc., lower alkylthio(lower)alkyl ester such as methylthiomethyl ester, ethylthiomethyl ester etc., halo(lower)alkyl ester such as 2-iodoethyl ester, 2,2,2-trichloroethyl ester etc., lower alkanesulfonyl(lower) alkyl ester such as mesylmethyl ester, mesylethyl ester etc., and aromatic esters, for example, optionally substituted aryl ester such as phenyl ester, tolyl ester, tert-butylphenyl ester, salicyl ester, 3,4-dimethyoxyphenyl ester etc., aryl(lower)alkyl ester such as benzyl ester, trityl ester, benzhydryl ester etc., as well as esters with silyl compound, for example, tri(lower)alkylsilyl ester such as trimethylsilyl ester, triethylsilyl ester etc., di(lower)alkyl(lower)alkoxysilyl ester such as dimethylmethoxysilyl ester, and diethylmethoxysilyl ester etc.

The term "esterified carboxy" may include carboxy which is transformed into esters as stated above.

The groups R³, R^(3'), R^(3a), R^(3a'), R^(3b) and R^(3b') may preferably attached at ortho-position in relation to the carbamoyl group.

The term "residue derived from alcohol having two or more carbon atoms by removing hydroxy group" may include alkyl group having two or more carbon atoms as well as alkyl group having one more carbon atoms which is substituted by non-alkyl substituent(s) having one or more carbon atoms. The said "alkyl group having two or more carbon atoms" may include lower alkyl group having two or more carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 6, or 2 to 5, or 2 to 4 carbon atoms, such as ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl etc. In the said "lower alkyl group having one or more carbon atoms which is substituted by non-alkyl substituent(s) having one or more carbon atoms", the term "non-alkyl substituent" may include groups containing heteroatoms such as oxygen, nitrogen, sulfur etc. which is combined directly or with intermediation of unsaturated group to the said alkyl group having one or more carbon atoms, and may also include aryl group. Example of preferable heteroatom is ester-oxygen (e.g. of carboxylic ester or carbonic ester). The said non-alkyl substituent(s) is preferably attached at the alpha-carbon atom of the said alkyl group. These no alkyl and alkyl groups preferably contain 1 to 10, especially 1 to 9, carbon atoms. Suitable examples of lower alkyl group having one or more carbon atoms which is substituted by non alkyl substituent(s) having one or more carbon atoms are acetoxymethyl, pivaloyloxymethyl, 1-(ethoxycarbonyloxy)ethyl, 3-phthalidyl, 2-(3-phthalidylidene)ethyl, (5-methyl-2-oxo-1,3-dioxole-4-yl)methyl etc. and groups which form physiologically hydrolyzable esters.

It is to be understood that, when the compound (I) or (I') has the chirality, the formula (I) or (I') includes all the isomers and mixtures thereof. It is also to be understood that, in the formula (Ik), two groups R may be identical or different and, when they are different, both of two isomers formed by geometry of --CH═C< double bond are included in the formula (Ik). Further, when these compounds show crystalline polymorphism or contain water or solvent of crystallization, all the crystal froms and crystals having such water or solvent are included in the scope of the present invention.

The processes for preparing the compound (I) are explained in details in the following.

Process (a)

The compound (Ib) can be obtained by converting the group R^(3a) and R^(3a') in the compound (Ia) into carboxy groups according to the conventional method. Any method conventionally used for removal of carboxy-protecting group such as hydrolysis, reduction etc. can be adopted as a method for the conversion.

The hydrolysis includes acidic hydrolysis and basic hydrolysis. Examples of acids used for acidic hydrolysis include inorganic and organic acids such as hydrochloric acid, formic acid, trifluoroacetic acid, benzenesulfonic acid, cation exchanger resin etc. Examples of bases used for basic hydrolysis include inorganic and organic bases such as alkali metal hudroxide e.g. sodium hydroxide, potassium hydroxide etc., alkali metal carbonate e.g. sodium carbonate, potassium carbonate etc., picoline, 1,5-diazabicyclo[4,3,0]-5-nonene, anion exchanger resin etc. The hydrolysis may be carried out in a solvent, examples for which include water, and a mixture of water and a hydrophylic organic solvent such as methanol, ethanol, tetrahydrofuran etc. The hydrolysis may also be carried out by solvolysis.

Process (b)

The compound (Id) can be obtained by reacting the compound (Ic) or its metal salt with the compound (II). The metal salt of the compound (Ic) can be prepared by reacting the compound (Ic) with alkali metal alkoxide. When the compound (Ic) is used without converting into its metal salt, the reaction is carried out in the presence of a base or a Lewis acid. Common organic or inorganic base such as pyridine, picoline, piperidine, morpholine etc. can be used. As the Lewis acid, boron trifluoride (etherate) titanium tetrachloride, zirconium tetrachloride, aluminum trichloride, tin tetrachloride, zinc dichloride etc. are used. The reaction is usually carried out in a solvent. Examples of the slovent include xylene, toluene, dioxane, dimethylformamide, dimethylsulfoxide etc. and any liquid base can serve as the solvent. The reaction is normally effected with heating.

A preferable example of operation is as follows. The compound (Ic) and 1,5 times by mole of the compound (II) is reacted under reflux in pyridine for 16-63 hours. After removing pyridine, the residue is treated under water, alkalinized by adding 10% aqueous ammonia under ice cooling and extracted with ether to remove the compound (II). The aqueous phase is acidified and crystals which appear are purified by column chromatography, recrystallization etc. to give the compound (Id).

The compound (Ic) can be prepared by the process (d) described infra (wherein A and B represent hydrogen).

The compound (II) is either the known compound commercially available or one which can be prepared by a method similar to that for production of the known compound.

Process (c)

The compound (Ie) can be obtained by reducing the compound (Id) according to the conventional method.

The reduction may either be effected by catalytic reduction or by chemical reduction. Tne catalytic reduction is carried out by reacting hydrogen in a solvent such as methanol, ethanol, dioxane etc. in the presence of metal catalyst for catalytic reduction such as platinum oxide, palladium on carbon, rhodium on alumina etc. The chemical reduction can be ettecting using reducing agent such as sodium borohydride-nickel chloride system in a solvent such as methanol, ethanol etc.

The compound (Id) is prepared by the process (b) described supra.

Process (d)

The compound (Ia) can be obtained by reacting simultaneously or stepwisely the compound (III) or reactive derivative at the carboxy group thereof with the compound (IV) and (IV') or reactive derivatives at the amino groups thereof.

When R² and R³ in the compound (IV) are identical to R^(2') and R^(3') in the compound (IV'), respectively, formulae (IV) and (IV') represent the same compound.

The reactive derivative at the carboxy group of the compound (III) includes acid halides, acid anhydrides, activated esters and activated amides. Among the acid halides, acid chloride is the most frequently used. Examples of the acid anhydrides include dialkylphosphoric acid mixed anhydride, dialkylphosphorous acid mixed anhydride, alkylcarbonic acid mixed anhydride, aliphatic carboxylic acid (e.g. pivalic acid, trichloroacetic acid) mixed anhydride etc. Examples of the activated esters include methyl ester, ethyl ester, cyanomethyl ester, p-nitrophenyl ester, an ester with N-hydroxysuccinimide etc. Examples of the activated amides include an amide with imidazol, dimethylimidazol or triazol. When this reaction is carried out stepwisely, two groups selected from carboxy or its reactive derivative are preferably different.

The reactive derivative at the amino group of the compound (IV) or (IV') includes a Schiff's base with an aldehyde (e.g. acetaldehyde, isopentanal, benzaldehyde), a reaction product with a silyl compound (e.g. trimethylsilyl chloride, trimethylsilylacetamide), a reaction product with a phosphorus compound (e.g. phosphorus trichloride, phosphorus oxychloride).

When the compound (III) is used in the form of carboxylic acid, it is advantageous to carry out the reaction in the presence of condensing agent. Examples of the condensing agent include N,N'-dicyclohexyl carbodiimide, N-cyclohexyl-N'-morpholinoethyl carbodiimide, N,N'-diisopropyl carbodiimide, N-ethylbenzisoxazolium salts, 2-chloro-1-methylpyridinium salt, N,N'-carbonyl diimidazol, phosphorus trichloride, phosphorus oxychloride etc.

The reaction is usually carried out in a solvent. Examples of the solvent include dioxane, methylene chloride, tetrahydrofuran, dimethylformamide, pyridine, benzene, toluene, xylene etc.

A preferable example of operation is as follows. Diethylester of the compound (III) and two times by mole of the compound (IV=IV') are heated in dry xylene under reflux for 20-48 hours. Crystals, if formed (when R³ =R^(3') =COOH), are filtered and if there is no crystal formation, the solvent is distilled off. Alternatively, the compound (IV=IV') is dissolved in dry dioxane and 1/2.66 times by mole of chloride of the compound (III) is added dropwise thereto. The mixture is stirred overnight.

The compound (III) and the compound (IV) or (IV') are either the known compound commercially available, or those which can be prepared by a method similar to that for production of the known compound.

Process (e)

The compound (If) can be obtained by esterifying the compound (Ib).

The esterification is carried out by reacting the compound (Ib) or a reactive derivative at the carboxy group thereof with an appropriate alcohol or a reactive derivative thereof. Examples of the reactive derivative at the carboxy groups of the compound (Ib) may be derivatives similar to those exemplified for the reactive derivative of the compound (III) and intramolecular cyclic anhydride formed by imidating the amido moiety, i.e. the compound of the formula: ##STR36## Examples of the reactive derivative of alcohol include active ester of the alcohol such as alkyl halide, alkyl sulfate etc. This reaction is carried out in a manner similar to that in the process (d). Especially desirable method is a reaction using alkyl halide in the presence of a base such as potassium carbonate and a solvent such as dimethylformamide, dioxane, hexamethylphosphoramide etc.

In a particular example, a compound of the formula: ##STR37## wherein R is residue derived from alcohol having two or more carbon atoms by removing hydroxy group, is prepared by reacting a compound of the formula: ##STR38## or a reactive derivative at the carboxy groups thereof with a hydroxy compound of the formula:

    R--OH

wherein R is as defined above, or a reactive derivative at the hydroxy group thereof.

Examples of the reactive derivative at the carboxy groups of the compound (Il) include acid halides, acid anhydrides, activated esters and activated amides. Among the acid halides, acid chloride is the most frequently used. Examples of the acid anhydrides include symmetric anhydride, an intramolecular cyclic anhydride formed by imidating the amido moeity, i.e. the compound of the formula: ##STR39## and mixed anhydrides, examples for which are dialkylphosphoric acid mixed anhydride, dialkylphosphorous acid mixed anhydride, alkylcarbonic acid mixed anhydride, aliphatic carboxylic acid (e.g. pivalic acid, trichloroacetic acid) mixed anhydride etc. Examples of the activated esters include cyanomethyl ester, p-nitrophenyl ester, an ester with N-hydroxysuccinimide etc. Examples of the activated amides include an amide with imidazol, dimethylimidazol or triazol.

Examples of the reactive derivative at the hydroxy group of the hydroxy compound include halide, inorganic acid esters such as sulfate etc. organic acid esters such as methanesulfonic acid ester, toluenesulfonic acid ester etc., alkaline metal salts and diazo-compounds. They can be represented by the formula: ##STR40## wherein Ra is a residue derived from R by removing one hydrogen attached to alpha-carbon atom, one of X and Y is hydrogen and the other is a reactive group or X and Y together form a group ═N₂. The reactive group means a group which can be easily left by the reaction.

When the compound (Il) is used in the form of carboxylic acid, it is advantageous to carry out the reaction in the presence of condensing agent. Examples of the condensing agent include N,N'-dicyclohexyl carbodiimide, N-cyclohexyl-N'-morpholinoethyl carbodiimide, N,N'-diisopropyl carbodiimide, N-ethylbenzisoxazolium salts, 2-chloro-1-methylpyridinium salt, N,N'-carbonyl diimidazol, phosphorus trichloride, phosphorus oxychloride etc.

In some cases, it is favorable to carry out the reaction in the presence of a base.

The reaction is usually carried out in solvent. Examples of the solvent include dioxane, methylene chloride, tetrahydrofuran, dimethylformamide, pyridine, benzene, toluene, xylene etc.

Suitable reactive derivative at the carboxy groups of the compound (Il), reactive derivative at the hydroxy group of the hydroxy compound R--OH, condensing agent, base, solvent etc. can be selected according to R in the desired compound (Ik). For example, where the group R is ethyl, propyl, isopropyl etc., the compound (Il) is preferable reacted with a compound R--X₁ wherein X₁ is halogene, preferably iodine in the presence of potassium (or sodium) carbonate as the base. Where the group R is 3-phthalidyl, 2-(3-phthalidylidene)ethyl, pivaloyloxymethyl, 1-(2-ethoxycarbonyloxy)ethyl, (5-methyl-2-oxo-1,3-dioxole-4-yl)methyl etc.,the compound (Il) is preferably reacted with the compound R--X₁ wherein X₁ is halogen in the presence of organic tertiary amine (e.g. triethylamine) as the base. In these cases, it is preferable to carry out the reaction in the presence of iodide (e.g. sodium iodide) when X₁ is chlorine. Where the group R is isopropyl, tertiary butyl etc., it is preferable to use the compound (Va) as the reactive derivative of the compound (Il), which is preferably reacted with a compound R--X₂ wherein X₂ is alkali metal, preferably lithium, sodium or potassium.

Process (f)

The compound (Ih) can be obtained by lower-alkylating the compound (Ig).

The lower-alkylation is effected according to the conventional method using a lower-alkylating agent such as methyl chloride, methyl iodide, ethyl bromide etc. This reaction is preferably carried out in the presence of a base.

When the compound (Ig) has a group being easily alkylated, such as carboxy, the said group is occasionally lower-alkylated in the course of the reaction, and such case is also included in the scope of the present invention.

The compound (Ig)is prepared by the processes (a) to (e) described supra (wherein R¹ is aryl substituted by hydroxy).

Process (g)

The compound (Ij) can be obtained by lower-alkylating the compound (Ii).

This process is conducted in a manner similar to that for the process (f). Examples of preferable bases include strong bases such as sodium hydride, sodium amide, sodium alkoxide etc.

The compound (Ii) is prepared by the process (a) to (e) described supra (wherein R¹ is pyrrolyl or indolyl).

Process (i)

The compound (Im) can be obtained by reacting the compound (Il) or a reactive derivative at the carboxy groups thereof with a methylating agent.

This reaction is conducted in a manner similar to that in the process (e).

Examples of the reactive derivative at the carboxy groups of the compound (Il) include acid halides, acid anhydrides, acivated esters and activated amides. Among the acid halides, acid chloride is the most frequently used. Examples of the acid anhydrides include symmetric anhydride, an intramolecular cyclic anhydride formed by imidating the amido moeity, i.e. the compound of the formula: ##STR41## and mixed anhydrides, examples for which are dialkylphosphoric acid mixed anhydride, dialkylphosphorous acid mixed anhydride, alkylcarbonic acid mixed anhydride, aliphatic carboxylic acid (e.g. pivalic acid, trichloroacetic acid) mixed anhydride etc. Examples of the activated esters include cyanomethyl ester, p-nitrophenyl ester, an ester with N-hydroxysuccinimide, trimethylsilylester etc. Examples of the activated amides include an amide with imidazol, dimethylimidazol or triazol.

As the methylating agent, methanol and reactive derivatives at the hydroxy group thereof can be used. Examples of the reactive derivative at the hydroxy group of methanol include halides, inorganic acid esters such as, sulfate etc., organic acid esters such as methanesulfonic acid ester, toluenesulfonic acid ester etc., alkaline metal salts and diazo-compounds. They can be represented by the formula: ##STR42## wherein one of X and Y is hydrogen and the other is a reactive group or X and Y together form a group ═N². The reactive group means a group which can be easily left by the reaction.

When the compound (Il) is used to react with methanol in the form of carboxylic acid, it is advantageous to carry out the reaction in the presence of condensing agent. Examples of the condensing agent include N,N'-dicyclohexyl carbodiimide, N-cyclohexyl-N'-morpholinoethyl carbodiimide, N,N'-diisopropyl carbodiimide, N-ethylbenzisoxazolium salts, 2-chloro-1-methylpyridinium salt, N,N'-carbonyl diimidazol, phosphorus trichloride, phosphorus oxychloride etc.

When the compound X--CH₂ --Y wherein X or Y is a reactive group selected from acid residue is used, it may be preferable to carry out the reaction in the presence of the base including inorganic base such as sodium carbonate, potassium carbonate etc. or organic base such as triethyl amine, pyridine etc.

The reaction is usually carried out in solvent. Examples of the solvent include dioxane, methylene chloride, tetrahydrofuran, dimethylformamide, pyridine, benzene, toluene, xylene etc.

In this reaction, suitable compound (Il) or the reactive derivative at the carboxy groups thereof, methylating agent and reaction conditions can be selected according to the reactant. For example, where the compound (Il) is used in the form of carboxylic acid, it is preferable to select the compound CH₃ -X₁ wherein X₁ is halogen, preferably iodine, as the reactant. In this case, the reaction is preferably carried out in the presence of the base (e.g. alkali metal carbonate). It is also preferable to carry out the reaction in the presence of iodide (e.g. sodium iodide) when X₁ is chlorine. Where the compound (Va) is used as the reactive derivative of the compound (Il), it is preferable to select a compound CH₃ --OX₂ wherein X₂ is alkaline metal, preferably lithium, sodium or potassium, as the methylating agent.

Process (ii)

The compound (Im) can be obtained by reacting the compound (In) or the metal salt thereof with benzaldehyde.

This reaction is conducted in a manner similar to that in the process (b).

The metal salt of the compound (In) can be obtained, for example, by reacting the compound (In) with alkali metal alkoxide. When the compound (In) is used without converting into its metal salt, the reaction is carried out in the presence of a base or a Lewis acid. Common organic or inorganic base such as pyridine, picoline, piperidine, morpholine etc. can be used. As the Lewis acid, boron trifluoride (etherate) titanium tetrachloride, zirconium tetrachloride, aluminum trichloride, tin tetrachloride, zinc dichloride etc. are used. The reaction is usually carried out in a solvent. Examples of the slovent include xylene, toluene, dioxane, dimethylformamide, dimethylsulfoxide etc. and any liquid base can serve as the solvent. The reaction is normally effected with heating.

Process (A)

The compound (V) can be obtained by subjecting the compound (Ip) to dehydrating reaction.

The dehydrating reaction may be carried out by heating in a non-aqueous solvent preferably with distilling-out of water, or by treating with dehydrating agent. Examples of the dehydrating agent include organic and incrganic acid halides such as oxalyl chloride, benzoyl chloride, phosphorus trichloride, phosphorus oxychloride, thionyl chloride etc., organic and inorganic acid anhydrides such as trifluoroacetic anhydride, phosphorus pentoxide, polyphosphoric acid etc., dehydrating condensing agent such as N,N'-dicyclohexylcarbodiimide, N-cyclohexyl-N'-morpholinoethylcarbodiimide, N,N'-diisopropylcarbodiimide, N-ethylbenzoisoxazolium salt, 2-chloro-1-methylpyridimium salt, N,N'-carbonyldimidazol, N,N'-thionyldiimidazol etc. and drying agent such as molecular sieve. The reaction is normally carried out in a solvent such as benzene, toluene, dimethylformamide, methylene chloride etc. Reaction temperature varies depending on the dehydrating agent and is normally between from room temperature to boiling point of the solvent.

Process (B)

The compound (V) can be obtained by reacting the compound (VI) with the compound R¹ --CHO.

This reaction is conducted in a manner similar to that in the process (b).

The reaction may be carried out in the presence of Lewis acid. As the Lewis acid, boron trifluoride (etherate), titanium tetrachloride, zirconium tetrachloride, aluminum trichloride, tin tetrachloride, zinc dichloride etc. are used. The reaction is usually carried out in a solvent. Examples of the solvent include xylene, toluene, dioxane, dimethylsulfoxide etc. The reaction is normally effected with heating. The starting compound (VI) is prepared by a process similar to the process (A) from 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bis benzoic acid.

It has been discovered by the inventors that some of the compound (I) or (I'), i.e. the compounds (Io) ##STR43## wherein R' is phenyl, 2-thienyl, 3-thienyl or 1-methyl-2-pyrrolyl, show a violent variation in melting point even if they are crystals obtained after a sufficient purification. Since this variation does not accompany a variation in purity, it is clear that the variation is not based on degradation of the compounds in question. Such variation in melting point is extremely inconvenient because it has adverse effects on slability and unity of formulations when the said compounds are formed into solid formulation such as tablets, powders, granules etc.

After extensive study on the case for the variation in melting point and method for preventing the same, the inventors discovered that the compounds showing such variation may be present in a lower melting point form (unstable form) and a higher melting point form (stable form), and the lower melting form can be converted into the higher melting form by subjecting to the treatment in which frictional forces act upon the lower melting point form. Such treatment includes crushing in a porcelein mortar or on a clay plate, pressing through a sieve, pressing in a vessel such as a filter, pressing into tablets, shaking in a mixer and grinding. The obtained higher melting point form does not change of itself into the lower melting point form. The higher melting point form does not cause problem on preparing solid formulations such as powders, granules, tablets etc. and can provide stable formulatins.

The lower melting point form of the compound (Io) is specified as follows.

The compound (Io) wherein R' is phenyl [(herein after referred to as the compound (I_(o) ^(a))] in lower melting point form can be obtained by recrystallizing the compound (I_(o) ^(a)) in an arbitrary form from methanol-water system and has the following physico-chemical properties.

melting point: 195°-196° C. (monohydrate).

IR(KBr, cm⁻¹): 3500, 2300-3300, 1680. NMR(DMSO-d₆, delta): 12.00 (1H, s, --CONH--), 11.7 (1H, s, --CONH--), 8.7-7.1 (m, aromatic H).

The compound (Io) wherein R' is 2-thienyl [(herein after referred to as the compound (I_(o) ^(b))] in lower melting point form can be obtained by recrystallizing the compound (I_(o) ^(b)) in an arbitrary form from methanol-water system and has the following physico-chemical properties.

melting point: 213°-215° C. (monohydrate).

IR(KBr, cm⁻¹): 3450, 2300-3300, 1680 . NMR(DMSO-d₆, delta): 12.0 (2H, s, --CONH--), 8.7-7.0 (m, aromatic H).

The compound (Io) wherein R' is 3-thienyl [(herein after referred to as the compound (I_(o) ^(c))] in lower melting point form can be obtained by recrystallizing the compound (I_(o) ^(c)) in an arbitrary form from methanol-water system and has the following physico-chemical properties.

melting point: 210°-212° C. (monohydrate).

IR(KBr, cm⁻¹): 3450, 2300-3300, 1680. NMR(DMSO-d₆, delta): 12.0 (1H, s, --CONH--), 11.8(1H, s, --CONH--), 8.7-7.1 (m, aromatic H).

The compound (Io) wherein R' is 1-methyl-2-pyrrolyl [(herein after referred to as the compound (I_(o) ^(d))] in lower melting point form can be obtained by recrystallizing the compound (I_(o) ^(d)) in an arbitrary form from methanol-water system and has the following physico-chemical properties.

melting point: 206°-209° C. (monohydrate).

IR(KBr, cm⁻¹): 2300-3300, 1680 .

NMR(DMSO- d₆, delta): 11.9 (1H, s, --CONH--),

11.8 (1H, s, --CONH--), 8.8-6.0 (m, aromatic H),

3.8(1H, s, --NCH₃).

The compound (Io) can be prepared by the following process. ##STR44##

When the groups R³ and/or R^(3') in the compound (I) or (I') is carboxy, any salts of such compound are also included within the scope of the invention. Examples of the salts include those with alkali metals such as sodium, potassium etc., alkali earth metals such as calucium, magnesium etc., other metals such as aluminum, organic amines such as ethanolamine, diethanolamine, pyrrolidine, piperidine, morpholine, N-methylpiperazine, N-hydroxyethylpiperazine, and amino acids such as lysine, arginine, ornitine, histidine, etc. These salts can be obtained by reacting the appropriate free carboxylic acid with the appropriate base.

In the compound (I) or (I') habing carboxy group as R³ and/or R^(3'), when said compound is not satisfactory in property such as solubility, stability, absorbability etc., a modified compound having improved properties may be obtained by converting the carboxy group in the original compound into a pharmaceutically acceptable derivative (i.e. bioprecursor). Such improved compound, when administered, is converted into the original carboxy compound in the body. Examples of these compound include those having pharmaceutically acceptable, physiologically hydrolyzable ester as R³ and R^(3'). The esters include methyl ester, ethyl ester, isopropyl ester, tert-butyl ester, acetoxymethyl ester, 1-(ethoxycarbonyloxy)ethyl ester, pivaloyloxymethyl ester, phthalidyl ester, 5-indanyl ester, 2-(3-phthalidylidene)ethyl ester, (5-methyl-2-oxo-1,3-dioxole-4yl)-methyl ester etc.

The compounds of the formula (I') have been shown to have anti-hyaluronidase, antiallergic and antiulcerous activities and accordingly are useful as medicine. Preferable compounds are those wherein both A and B are other than hydrogen. Also, preferable compounds are those wherein groups R³ and R^(3') are attached at ortho-position to the carbamoyl (--CONH--) groups. In addition, the compounds (I) have an advantage that they are less toxic.

For example, the compounds (Ik), (Im) and (V) have the allergic activity. It is considered that these compounds are converted in the body to the parent compounds having free carboxyl groups, however, in some cases the compounds (Ik), (Im) and (V) are superior to the parent compounds in solubility, stability, absorbability etc. and accordingly show an excellent effect.

For the above usages, the required dose will, of course, vary depending on the compound actually used, the mode of administration and treatment desired. In general, however, satisfactory results are obtained in administration at a dosage from 1 to 6 mg/kg conveniently administered in 2 to 4 divided dosages a day or in sustained release form.

For prophylactic and/or therapeutic administration, the compound according to the invention can be used in a form of conventional pharmaceutical preparation which contains the said compound, as an active ingredient, in admixture with pharmaceutically acceptable carriers such as organic or inorganic, solid or liquid excipient which is suitable for oral, parenteral or external administration. The pharmaceutical preparation may be in solid forms such as capsule, tablet, sugar coated tablet, ointment, suppository etc. or in liquid forms such as solution, suspension, emulsion etc. These preparations also may contain auxiliary substance, stabilizer, humectant, emulsifier, buffer and other conventional additives.

Practical and preferred embodiments of the present invention are illustrated in further detail by the following Examples and Test Examples. In the following experiments, there were used Art 5735 made by Merck as silica gel for TLC and Art 7734 made by Merck as silica gel for column chromatography.

EXAMPLE 1 Preparation of 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid (Compound 01) (Process d)

Diethyl malonate (3.48 g, 21.7 mmol) and anthranilic acid (6.0 g, 43.7 mmol) were heated under reflux in dry xylene (120 ml) for 40 hours. The precipitated crystals were filtered while hot and washed with acetone to give white crystals of the title compound (6.19 g, 83.2%). m.p., 254°-258° C.

EXAMPLE 2 Preparation of 4,4'-dinitro-2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid (Compound 06) (Process d)

4-Nitroanthranilic acid (5.0 g, 26.6 mmol) was dissolved in dry dioxane (130 ml). To this solution, a solution of malonyl dichloride (1.45 g) in dry dioxane (5 ml) was added dropwise at room temperature. After stirring the mixture overnight, the precipitated crystals were collected by filtration, and washed with water and ether to give a pale yellow crystals of the title compound (2.58 g, 9.8%). m.p., 269°-270.5° C.

EXAMPLE 3 Preparation of 4-chloro-2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid (Compound 09) (Process d)

To the solution of anthranilic acid (1.824 g, 13.3 mmol) in dry dioxane (65 ml), ethyl malonyl chloride (1.001 g, 0.851 ml, 6.65 mmol) in dry dioxane (2.5 ml) was added dropwise at room temperature and the mixture was stirred at room temperature for 3 hours, then at 50° C. for 1 hour. After the reaction, the precipitated solid matter was filtered, and the solvent was removed from the filtrate under reduced pressure. The residue was dissolved by the addition of ethyl acetate and washed with 1N.HCl to remove anthranilic acid. Then the organic layer was washed with water and dried. Ethyl acetate was evaporated under reduced pressure to give a yellow oil. The obtained oil was purified by applying on a silica gel column [(developing solvent: ethyl acetate:benzene=1:1 (containing 1% acetic acid)], from which the third, colorless fraction was collected to give O-ethyl malonyl aminobenzoic acid in pale yellow oil. The oil was treated with ethyl acetate, washed and dried. The solvent was evaporated to give an intermediate product of O-ethyl malonyl aminobenzoic acid in pale yellow solid (721 mg, 43%). m.p., 103°-104° C.

The thus obtained intermediate (500 mg, 1.99 mmol) and 4-chloro-anthranilic acid (341 mg, 1.99 mmol) were refluxed in dry xylene (13 ml) for 14 hours. The precipitated crystals were filtered while hot and washed with acetone to give the title compound as white crystals (483 mg, yield, 64.5%). m.p., 259°-261° C.

EXAMPLE 4 Preparation of 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoic acid (Compound 11) (Process b)

2,2'-[(1,3-Dioxo-1,3-propanediyl)diimino]bisbenzoic acid (1.0 g) and benzaldehyde (0.46 g, 1.5 mol equivalent) were heated under reflux in dry pyridine (8 ml) for 16 hours. After removing pyridine, the mixture was treated with water, made alkaline with 10% aqueous ammonia under ice cooling, and the aqueous layer was washed with ether. The aqueous layer was made acidic (pH=2) with 1N HCl, and the precipitated crystals were collected by filtration. After washing with water, the resulting solid was purified by dissolving in tetrahydrofuran, adsorbing on the silica gel column and separating the desired compound using a developing solvent [ethyl acetate:benzene=1:1 (containing 1% acetic acid)]. After removing the initially eluted impurities, the solvent was removed from the effluent out liquid containing the desired compound. The residue was crystallized by adding water, collected on a filter, washed with water, and dried to give the title compound (0.686 g, yield, 51%), which was recrystallized from the mixed solvent of CH₃ OH-H₂ O system to obtain pale yellow crystals of monohydrate (Crystal a, 0.507 g) (Drying: 1 mm Hg, 100° C., 15 hours), m.p., 195°-196° C.

Elementary analysis: Calcd. for C₂₄ H₁₈ N₂ O₆.H₂ O: C64.28, H4.50, N6.25. Found: C64.23, H4.50, N6.25.

Rf=0.53 [Ethyl acetate:benzene=1:1 (containing 1% acetic acid)

IR(KBr, cm⁻¹): 3500(--CONH--), 2300-3300(--COOH), 1680(--CONH--) (FIG. 1).

¹ H-NMR(DMSO-d₆, δ): 12.00 (s,1H, --CONH--, 11.7 (s, 1H, --CONH--), 8.7-7.1 (m, aromatic hydrogen) (FIG. 2; solvent is CDCl₃ :DMSO-d₆ =3:1).

MS (m/e):412 (M⁺ -18).

Recrystallization by the use of CH₃ OH in place of CH₃ OH--H₂ O system gave crystals of 1/2 hydrate (Crystal b), m.p., 195°-196° C.

Elementary analysis: Calcd. for C₂₄ H₁₈ N₂ O₆.1/2H₂ O: C65.60, H4.32, N6.38. Found: C65.44, H4.47, N6.39.

In another run, the eluent from the column gave, on removal of solvent and addition of water, crystals, which were re-crystallized from CH₃ OH, followed by re-crystallization from CH₃ OH--H₂ O giving the crystals of m.p., 247°-249° C. (Crystal c).

Elementary analysis: Calcd. for C₂₄ H₁₈ N₂ O₆.H₂ O: C64.28, H4.50, N6.25. Found: C64.28, H4.36, N6.45.

IR(KBr, cm⁻¹): 3500(--CONH--), 2300-3300(COOH), 1680(--CONH--) (FIG. 3).

¹ H-NMR(DMSO-d₆, δ): 12.00 (s, 1H, CONH--), 11.7 (s, 1H, --CONH--) 8.7-7.1 (m, aromatic hydrogen) (FIG. 4; solvent: CDCl₃ :DMSO-d₆ =3:1).

EXAMPLE 5 Preparation of Diethyl 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 14) (Process b)

Diethyl 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoate (1.0 g, 2.51 mmol) and benzaldehyde (400 mg, 3.76 mmol) were heated under reflux in dry pyridine (8 ml) for 24 hours. After removal of pyridine, the residue was treated with water (20 ml), which was made acidic with 10% HCl under ice cooling. The resulting acidic solution was extracted with chloroform. The organic layer was washed with water, dried, concentrated to give brown oil (1.332 g), which was purified by silica gel column chromatography (firstly benzene, followed by benzene:ether=97:3). After removing the solvent from the eluent of the desired compound, the residue was crystallized by the use of n-hexane to give the title compound (384 mg, yield, 31%) in white solid. Recrystallization from the mixed solvent of CH₃ OH--H₂ O gave a solid (280 mg). m.p., 139°-140° C. Rf=0.39 [benzene:ether=95:5] IR(KBr, cm⁻¹): 3250 (--CONH--), 1700 (--COOEt), 1680 (--CONH--), ¹ H-NMR (DMSO-d₆, δ): 11.91 (s, 1H, CONH), 11.38 (s, 1H, CONH) 3.94-4.54 (qq, 4H, CH₂ CH₃), 1.13-1.48 (tt, 6H, --CH₂ CH₃), 6.90-8.90 (m, aromatic hydrogen).

MS (m/e): 486 (M⁺).

EXAMPLE 6 Preparation of 2,2'-[[2-(3,4-dimethoxy)phenylmethylene-1,3-dioxo-1,3-propanediyl]diimino]bisbenzoic acid (Compound 20) (Process b)

2,2'-[(1,3-Dioxo-1,3-propanediyl)dimino]bisbenzoic acid (1.0 g, 2.92 mmol) and 3,4-dimethoxybenzaldehyde (0.73 g, 4.38 mmol) were heated under reflux in dry pyridine (8 ml) for 16 hours. After removal of pyridine, the mixture was treated with water, made alkaline with 10% aqueous ammonia under ice cooling, and extracted with ether. The aqueous layer was made acidic with 1N HCl under ice cooling to form solid, which was collected by filtration and washed with water. The resulting crude product was dissolved in THF, and purified by silica gel column chromatography [developing solvent: benzene:ethyl acetate=1:1 (containing 1% acetic acid)]. After removal of the eluted impurities, the effluent containing the desired compound is collected. The solvent was evaporated and the residue was treated with water to form crystals, which were collected on filter and washed with water to give a pale yellow solid of the title compound (0.614 g, yield, 43%). Recrystallization from the mixed solvent of MeOH--H₂ O system gave a solid (0.462 g). m.p., 213°-214° C.

Rf=0.19 [ethyl acetate:benzene=1:1 (containing 1% acetic acid).

IR (KBr, cm⁻¹): 3500 (--CONH--), 2300-3200 (--COOH), 1680 (--CONH--).

¹ H-NMR (DMSO-d₆, δ): 12.0 (s, 1H, CONH), 11.80 (s, 1H, CONH)8.7-6.9 (m, aromatic hydrogen).

MS (m/e): 472 (M⁺ -18).

EXAMPLE 7 Preparation of 2,2'-[[1,3-dioxo-2-(4-methyl)phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid (Compound 26) (Process b)

2,2'-[(1,3-Dioxo-1,3-propanediyl)diimino]bisbenzoic acid (1.0 g, 2.92 mmol) and 4-methylbenzaldehyde (0.54 g, 4.38 mmol) were heated under reflux in dry pyridine (12 ml) for 16 hours. After removing pyridine, the mixture was treated with water (30 ml) and made alkaline with 10% aqueous ammonia under ice cooling. After washing with ether, the aqueous layer was made acidic with 1N HCl under ice cooling, and the precipitated solid was collected on filter and washed with water. Recrystallization of this solid from MeOH--H₂ O system gave the title compound (539 mg, yield, 42%) in white solid. m.p., 230°-233° C.

Rf=0.25 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

IR (KBr, cm⁻¹): 3450 (CONH), 3300-2200 (COOH), 1680 (CONH).

¹ H-NMR(DMSO-d₆, δ): 12.0 (s, 1H,CONH), 11.7 (s, 1H, CONH), 2.3 (s, 3H , CH₃), 8.7-7.0 (m, aromatic hydrogen). MS (m/e): 426 (M⁺ -18).

EXAMPLE 8 Preparation of 2,2'-[[1,3-dioxo-2-(4-nitro)phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid (Compound 36) (Process b)

2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid (1.0 g, 2.92 mmol) and 4-nitrobenzaldehyde (0.66 g, 4.38 mmol) were heated under reflux in dry pyridine (12 ml) for 16 hours. After distilling off pyridine, the mixture was treated with water (30 ml) and with 10% aqueous ammonia under ice cooling to make alkaline, and washed with ether. The aqueous layer was made acidic with 1N.HCl, and the precipitated crystals were collected by filtration and washed with water. As the resulting solid was soluble only partly in THF, it was first subjected to separation between the soluble and the insoluble portions. As the insoluble solid gave one spot on TLC, the soluble portion was subjected to column purification [developing solvent: ethyl acetate:benzene=1:1 (containing 1% acetic acid)]. After removing the first eluting impurities, the effluent containing the desired compound was collected, and the solvent was evaporated. The residue was treated with water to give crystals, which were collected on filter, and then washed with water. The previous insoluble solid and the cystals were combined to give the title compound in white solid (884 mg, yield, 64%). The resulting product was recrystallized from the mixed solution of CH₃ OH--THF--H₂ O system to give a solid (642 mg). m.p., 275°-276° C.

Rf=0.23 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

IR (KBr, cm⁻¹): 3540 (--CONH--), 3300-2200 (COOH), 1680 (--CONH--).

¹ H-NMR(DMSO-d₆, δ): 12.1 (s, 1H, CONH), 11.6 (s, 1H, CONH), 8.8-7.1 (m, aromatic hydrogen). MS(m/e): 457 (M⁺ -18).

EXAMPLE 9 Preparation of 2,2'-[[1,3-dioxo-2-(2-thienyl)methylene-1,3-propanediyl]diimino]bisbenzoic acid (Compound 40) (Process b)

2,2'-[(1,3-Dioxo-1,3-propanediyl)diimino]bisbenzoic acid (1.0 g, 2.92 mmol) and 2-thiophenealdehyde (0.49 g, 4.38 mmol) were heated under reflux in dry pyridine (8 ml) for 16 hours. After removing pyridine, the mixture was treated with water, made alkaline with 10% aqueous ammonia under ice cooling, and washed with ether. The aqueous layer was made acidic with 1N.HCl under ice cooling, and the precipitated crystals were collected on filter and washed with water. The resulting solid was purified by silica gel column chromatography and the effluent containing the desired compound was collected. After removing solvent, the residue was crystallized by treating water, collected by filtration, washed with water, and dried to give the title compound (0.730 g, yield, 57%), which was recrystallized from the mixed solvent of CH₃ OH--H₂ O to give the pale yellow crystals (0.602 g). m.p.: 213°-215° C.

Rf=0.35 [ethyl acetate:benzene=1:1 (containing 1% acetic acid).

IR (KBr, cm⁻¹), 3450 (--CONH--), 3300-2300 (COOH), 1680 (--CONH--).

¹ H-NMR (DMSO-d₆, δ): 12.0 (s, 2H, CONH), 8.7-7.0 (m, aromatic hydrogen). MS (m/e): 418 (M⁺ -18).

EXAMPLE 10 Preparation of 4-chloro-2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimimo]bisbenzoic acid (Compound 46) (Process b)

Benzaldehyde (168.7 mg, 0.162 ml, 1.59 mmol) and the compound (09) prepared in Example 3 (400 mg, 1.06 mmol) were refluxed in dry pyridine (4 ml) for 17.5 hours. After removing pyridine under reduced pressure, water was added, and the mixture was made alkaline with 10% aqueous ammonia under ice cooling, which was treated with NaCl and washed with ether (30 ml×5).

The aqueous layer was made acidic with 1N.HCl (pH=2) under ice cooling, and the precipitated solid was collected on filter and washed with water. The resulting solid was dissolved in THF, and purified using silica gel column [developing solvent, ethyl acetate:benzene=1:1 (containing 1% acetic acid)]. After removing the solvent from the colorless third effluent solution, the resulting solid was sufficiently washed with water to give the title compound (226.7 mg, yield, 46%). The obtained product was recrystallized from CH₃ OH--H₂ O system to give a purified product. The obtained compound was found to be a mixture of two kinds of E-form and Z-form at the rate of 1:1 from the following data.

White crystals, m.p., 153°-156° C.

Rf=0.27 and 0.23 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

IR (KBr, cm³¹ 1): 3700-2200 (--CONH, --COOH), 1685 (CONH).

¹ H-NMR (DMSO-d₆, δ): 12.08 and 11.80 (CONH of E or Z form), 11.98 and 11.68 (CONH, of E or Z form), 8.86-7.00 (m, aromatic hydrogen).

MS (m/e): 446 (M⁺ -18).

EXAMPLE 11 Preparation of disodium 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 49)

To methanol (2 ml), 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoic acid (500 mg) and 1N.NaOH (2.32 ml) were added, and the mixture was stirred at room temperature for 1 hour. Solvent was removed from the reaction mixture, and the residue was treated with acetone and crystallized to give the title compound (478 mg, 87%) in white solid. m.p. 283° C. (dec.)

Rf=0.26 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

EXAMPLE 12 Preparation of 2,2'-[(1,3-dioxo-2-phenylmethyl-1,3-propanediyl)diimino]bisbenzoic acid (Compound 50) (Process c)

(a) The compound (11) (0.5 g, 1.16 mmol) prepared in Example 4 was subjected to catalytic hydrogenation by hydrogen gas over 10% Pd/C (0.1 g), at room temperature for 24 hours. After filtering off Pd/C, and washing the catalyst with THF, the solvent was evaporated to give the title compound in pale brown crystals. The product was recrystallized from the mixed solvent of CH₃ OH--H₂ O system (amount, 0.384 g, yield, 76%). m.p., 234°-236° C.

Rf=0.12 [ethyl acetate:benzene=1:1 (containing 1% acetic acid).

IR(KBr, cm⁻¹), 3300-2300 (--CONH--, COOH), 1680 (--CONH--).

¹ H-NMR(DMSO-d₆, δ): 11.6 (s, 2H, --CONH--), 8.5-7.0 (m, aromatic hydrogen), 3.9 (t, 1H, --CH<) 3.3 (d, 2H, --CH₂ -).

MS (m/e): 414 (M⁺ -18).

(b) Compound (11)(500 mg, 1.16 m mol) and NiCl₂.6H₂ O (551 mg, 2.32 m mole) were dissolved in methanol (25 ml). On adding NaBH₄ (438.8 mg, 11.6 m mole) in small portions to the solution while attention being paid to the generation of hydrogen gas under ice cooling, the reaction mixture turned black. After addition of NaBH₄ (about 1 hour), the solution was further stirred at room temperature for 30 minutes. The black solid was collected on filter, and sufficiently washed with methanol. The filtrate was combined from which the solvent was removed under reduced pressure. The residue was treated with water, made acidic (pH 2) with 10% HCl, and the precipitated solid was collected on filter, washed with water, and dried to give white solid. This solid was dissolved in THF and purified by silica gel column chromatography [developing solvent: ethyl acetate: benzene=1:1 (containing 1% acetic acid)]. After the purification, the resulting solid was sufficiently washed with water and dried to give the title compound (280 mg, yield, 56%) as a white solid.

The compound obtained here showed full agreements in TLC and spectral data with the reduced product obtained in (a) above.

EXAMPLE 13 Preparation of 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoic acid (Compound 11) (Process a)

The compound (14) (100 mg, 0.205 mmol) and 1N.NaOH (0.61 ml, 0.61 mmol) were refluxed in methanol (0.61 ml) for 45 minutes. After removing the solvent under reduced pressure, the mixture was treated with 10% hydrochloric acid under ice cooling to make acidic (pH 2) to precipitate solid, which was collected on filter. The resulting product was washed with water and dried to give a white solid (81.5 mg), which was dissolved in THF and purified by silica gel column chromatography [developing solvent: ethyl acetate: benzene, 1:1 (containing 1% acetic acid)]. After removal of the solvent from the first eluent, the obtained solid was sufficiently washed with water to give the title compound (37.1 mg, yield, 42%).

The obtained product showed full agreement in its TLC, melting point, and spectral data with the compound obtained in Example 4.

EXAMPLE 14 Preparation of diethyl 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 14) (Process e)

The compound (11) prepared in Example 4 (430 mg, 1 mmol) was dissolved in dry acetone (10 ml) and dry DMF (1 ml). To the solution K₂ CO₃ (276 mg, 2 mmol) was added, to which C₂ H₅ I (0.191 ml, 374 mg, 2.4 mmol) was added dropwise. After addition of DMF (6 ml), the mixture was stirred at 60° C. for 2 hours. The reaction solution was poured into ice water (70 ml) and extracted three times with ethyl acetate. The extract was washed with water and dried. The solvent was evaporated under reduced pressure to give the title compound (480 mg, yield, 98%) as pale yellow solid. m.p., 139°-141° C.

The resulting product fully agreed with the compound (14) prepared in Example 5 in IR and NMR spectra.

EXAMPLE 15 Preparation of 2,2'-[(1,3-dioxo-2-phenylmethyl-1,3-propanediyl)diimino]bisbenzoic acid (Compound 50) (Process d)

Diethylbenzyl malonate (2.0 g, 1.85 ml, 7.99 mmol) and anthranilic acid (2.19 g, 15.98 mmol) were refluxed in dry xylene (44 ml) for 22.5 hours. After removing the solvent from the reaction solution under reduced pressure, the residue was dissolved in THF, and the solution was subjected to column purification [developing solvent, ethyl acetate:benzene=1:1 (containing 1% acetic acid)]. The initially flowing out several kinds of impurities were discarded the title compound was eluted as a colorless solution. After removal of the solvent, the resulting solid was sufficiently washed with water to give the title compound (250 mg, yield, 7%), which was recrystallized from the mixed solvent of CH₃ OH--H₂ O system. Yield, 190 mg.

Rf=0.12 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

The product obtained showed full agreement with that prepared by hydrogenation in Example 12 in IR and NMR spectra.

EXAMPLE 16 Preparation of dimethyl 2,2'-[[2-(3,4-dimethoxy)phenylmethylene-1,3-dioxo-1,3-propanediyl]diimino]bisbenzoate (Compound 47) (Process f)

The compound (24) (0.5 g, 1.05 mmol) was dissolved in dry acetone (13 ml), K₂ CO₃ (0.435 g, 3.15 mmol) and methyl iodide (0.52 g, 0.229 ml, 3.68 mmol) were added in this order. The mixture was heated to 60° C, and the precipitated potassium salt was dissolved by adding dry DMF (5 ml) thereto to form a yellow-brown solution. The resultant was further stirred at 60° C. for 30 minutes, whereupon the reaction solution changed to green color. The reaction mixture was poured into water, made weak acidic with 1N.HCl, and extracted three times with ethyl acetate. The organic layer was washed with water, then with saturated brine, dried, and evaporated. The residual yellow oil was crystallized from isopropyl ether to give the title compound (0.458 g, yield, 84%) as pale yellow crystals, which was recrystallized from the mixed solvent of THF--CH₃ OH--H₂ O system. Yield, 0.391 g. m.p., 157°-158° C.

Rf=0.44 (ethyl acetate:benzene=4:1)

IR (KBr, cm⁻¹), 3250 (CONH), 1700 (COOCH₃), 1680 (CONH).

¹ H-NMR (DMSO-d₆, δ): 11.4 (s, 1H, CONH), 11.1 (s, 1H, CONH), 8.7-7.0 (m, aromatic hydrogen), 3.85 (s, 3H, COOCH₃), 3.80 (s, 3H, 4--CH₃ O--), 3.65 (s, 3H, COOCH₃), 3.55 (s, 3H, 3--CH₃ O--).

MS (m/e): 587 (M⁺).

EXAMPLE 17 Preparation of dimethyl 2,2'-[[1,3-dioxo-2-(1-methyl-1H-pyrol-2-yl)methylene-1,3-propanediyl]diimino]bisbenzoate (Compound 48) (Process g)

Into a mixture of NaH (57.1 mg, 1.43 mmol) and dry DMF (0.5 ml), a solution of the compound (42) (200 mg, 0.48 mmol) in dry DMF (1.5 ml) was added dropwise, and the mixture was stirred at room temperature for 10 minutes, after which the mixture was treated with methyl iodide (222.9 mg, 0.097 ml, 1.57 mmol) and stirred at room temperature for 5.5 hours. The reaction mixture was poured into ice water (50 ml), and extracted with ethyl acetate. The organic layer was washed with water and dried. The solvent was evaporated under reduced pressure to give yellow oil (359.8 mg). The obtained oil was purified by column chromatography [developing solvent, ethyl acetate: benzene=1:1 (containing 1% acetic acid)]. Solvent was removed from the first effluent yellow solution, and the obtained yellow oil was crystallized with isopropyl ether to give the title compound (50 mg, yield, 23%) as a yellow solid, which was recrystallized from the mixed solvent of CH₃ OH--H₂ O system. m.p., 157°-158° C.

Rf=0.66 [ethyl acetate:benzene=1:1 (containing 1% acetic acid)].

IR (KBr, cm⁻¹): 3270 (CONH), 1698 (--COOCH₃), 1670 (--CONH--).

¹ H-NMR (DMSO-d₆, δ): 11.30 (s, 1H, CONH), 11.23 (s, 1H, CONH), 8.80-6.00 (m, aromatic hydrogen), 3.78 (s, 3H, N--CH₃), 3.70 (s, 3H, --COOCH₃) MS (m/e): 461 (M⁺).

The obtained product showed full agreement in TLC IR, and NMR with the product prepared by esterifying the compound (43) according to Example 16 by the use of CH₃ I--K₂ CO₃ system.

In a similar manner to the above Examples, there were obtained the compounds shown in the following Table. In the Table, the positions of the bonds attached to the groups R², R² ', R³, and R³ ' are shown, for convenience, by the position numbers based on the bonding position of --CONH--taken as 1, as in the illustration. (Accordingly, the position numbers in the table differ frequently from the numbers in the usual nomenclature.) Further, the processes for producing the compounds are shown by the Numbers of Examples in which the compounds were actually produced or in which similar reaction systems were used.

    __________________________________________________________________________      ##STR45##                                                                

    __________________________________________________________________________     Compound                                                                             Example                                                                             A,B  R.sup.2,R.sup.2'                                                                     R.sup.3,R.sup.3'                                                                     mp (°C.)                                                                     .sup.1 HNMR(δ,DMSOd.sub.6)              __________________________________________________________________________     01    1    H,H  H     2,2'-COOH                                                                            254-258                                                                              ##STR46##                                    02    1    "    H     3,3'-COOH                                                                            290-297                                                                              ##STR47##                                    03    1    "    H     4,4'-COOH                                                                            >300                                                                                 ##STR48##                                    04    1    "    H     2,2'-COOEt                                                                           137-140                                                                              ##STR49##                                    05    1    "    5,5'-Cl                                                                              2,2'-COOH                                                                            292-293.5                                                                            ##STR50##                                    06    2    "    5,5'-NO.sub.2                                                                        2,2'-COOH                                                                            269-270.5                                                                            ##STR51##                                    07    1    "    4,4'-CH.sub.3                                                                        2,2'-COOH                                                                            257-258                                                                              ##STR52##                                    08    2    "    2,2'-OCH.sub.3                                                                       5,5'-COOH                                                                            283-287                                                                              ##STR53##                                    09    3    "    H,5'-Cl                                                                              2,2'-COOH                                                                            259-261                                                                              ##STR54##                                    __________________________________________________________________________      Note:                                                                          01-03 are known compounds.                                                    Compound                                                                             Example                                                                             A,B  R.sup.1     R.sup.2,R.sup.2'                                                                     R.sup.3,R.sup.3'                                                                      mp (°C.)                                                                       Yield (%)                      __________________________________________________________________________     11    1,4,13    C.sub.6 H.sub.5                                                                            H     2,2'-COOH                                                                             195-196                                                                               51                                   *1                                                                       12 13 14 15 16                                                                       1,4 1,4 1,5,14 1,4 2,4                                                               ##STR55##                                                                          " " " " "   " " " 5,5'-Cl 5,5'-NO.sub.2                                                          3,3'-COOH 4,4'-COOH 2,2'-CO.sub.2                                              C.sub.2 H.sub.5 2,2'-COOH "                                                           293-294 278-280 139-140 245-246.5                                               272-273                                                                              30 30 31 40 53                 17    1,4       "           4,4'-CH.sub.3                                                                        "      240-242                                                                               34                             18    2,4       "           2,2'-OCH.sub.3                                                                       5,5'-COOH                                                                             290-291                                                                               12                             19    1,4       4-CH.sub. 3 OC.sub.6 H.sub.4                                                               H     2,2'-COOH                                                                             216-219                                                                               47                             20    1,6       3,4-(CH.sub.3 O).sub.2C.sub.6 H.sub.3                                                      "     "      213-214                                                                               43                                   *2                                                                       21    1,6       "           5,5'-Cl                                                                              "      282-286                                                                               52                             22    2,6       "           5,5'-NO.sub.2                                                                        "      271-273                                                                               58                             23    1,6       3,4,5-(CH.sub.3 O).sub.3C.sub.6 H.sub.2                                                    H     "      194-196                                                                               48                             24    1,6       3-CH.sub.3 O4-HOC.sub.6 H .sub.3                                                           "     "      187-189                                                                               30                             25    1,6       3,4-(OCH.sub.2 O)C.sub.6 H.sub.3                                                           "     "      209-210                                                                               42                             26    1,7       4-H.sub.3 CC.sub.6 H.sub.4                                                                 "     "      230-233                                                                               42                             27    1,4       4-(CH.sub.3).sub.2 CHC.sub.6 H.sub.4                                                       "     "      218-221                                                                               44                             28    1,4       4-(CH.sub.3).sub.2 NC.sub.6 H.sub.4                                                        "     "      223-225                                                                               61                             29    1,7       4-CH.sub.3 CONHC.sub.6 H.sub.4                                                             "     "      288-289                                                                               38                             30    1,4       4-ClC.sub.6 H.sub.4                                                                        H     2,2'-COOH                                                                             261-262                                                                               44                             31 32 33 34 35                                                                       1,4 1,4 1,4 1,6 1,4                                                                  ##STR56##                                                                          3-ClC.sub.6 H.sub.4 2-ClC.sub.6 H.sub.4 4-BrC.sub.6                            H.sub.4 4-FC.sub.6 H.sub.4 4-F.sub.3 CC.sub.6 H.sub.4                                      " " " " "                                                                            " " " " "                                                                             229-230 228-230 262-264 238-240                                                235-237                                                                               73 40 57 41 46                 36    1,8       4-O.sub.2 NC.sub.6 H.sub.4                                                                 "     "      275-276                                                                               64                             37    1,4       4-NCC.sub.6 H.sub.4                                                                        "     "      280-282                                                                               47                             38    1,4       1-naphthyl  "     "      237-239                                                                               34                             39    1,4       2-furyl     "     "      214.5-216.5                                                                           41                             40    1,9       2-thienyl   "     "      213-215                                                                               57                             41    1,4       3-thienyl   "     "      210-212                                                                               46.5                           42    1,4       2-pyrrolyl  "     "      247-250(dec)                                                                          56                             43    1,4       1-methyl-2-pyrrolyl                                                                        "     "      205-207(dec)                                                                          61                                   *3                                                                       44    1,4       3-pyridyl   "     "      259-261                                                                               39                             45    1,4       1-methyl-3-indolyl                                                                         "     "      233-234                                                                               41                                   *3                                                                       46    3,10      C.sub.6 H.sub.5                                                                            H,5-Cl                                                                               "      153-156                                                                               46                             47    1,6,16    3,4-(CH.sub.3 O).sub.2C.sub.6 H.sub.3                                                      H     2,2'-COOCH.sub.3                                                                      157-158                                                                               84                             48 49 1,4,17 1,4,11                                                                        ##STR57##                                                                          1-methyl-2-pyrrolyl C.sub.6 H.sub.5                                                        H "   2,2'-COOCH.sub.3 2,2'-COONa                                                           157-158 283                                                                           23 87                          50    1,4,12,15                                                                            ##STR58##                                                                          C.sub.6 H.sub.5                                                                            "     2,2'-COOH                                                                             234-236                                                                               76                             __________________________________________________________________________      Note                                                                           *1 : This compound can be also obtained by hydrolysis of Compound 14           (Process a).                                                                   *2 : This compound can be obtained by methylation of Compound 24 (Process      f) and hydrolysis of ester.                                                    *3 : This compound can be obtained by methylation of corresponding             NHcompound (Process g) and hydrolysis of ester.                          

EXAMPLE 18 Preparation of corresponding dimethyl ester (Compound 51) from 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3propanediyl)diimino]bisbenzoic acid (Compound 11)

To the solution of the Compound (11) [obtained from benzaldehyde and 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoic acid in a yield of 72%] (3.0 g, 6.97 mmol) were added anhydrous potassium carbonate (1.92 g, 13.9 mmol) and then dry dimethylformamide (DMF) (9 ml). When the resulting solution was treated with methyl iodide (2.37 g=1.04 ml, 16.7 mmol), a white solid precipitated, which was dissolved by further addition of dry DMF (20 ml). After stirring at 60° C. for 50 minutes, the reaction solution was extracted three times with ethyl acetate. The organic layer was washed with water and dried over Na₂ SO₄. The solvent was evaporated and the yellow viscous residue was crystallized from isopropyl ether to give pale yellow solid of the desired compound. (2.9 g, yield, 91%). m.p., 110°-111° C.

Rf=0.62 (benzene:ether=9:1, silica gel).

IR (KBr, cm⁻¹): 3300, 1700, 1605.

1H-NMR(CDCl₃, δ): 11.9 (S, 1H, --CONH--), 11.3 (S, 1H, --CONH--), 6.9-9.0 (m, 14H, aromatic hydrogen, vinyl hydrogen), 3.9 (S, 3H, --COOCH₃), 3.6 (S, 3H, --COOCH₃).

EXAMPLE 19 Preparation of Compound 51 from 2,2'-phenylethenilidenebis(3,1-benzoxazine-4-one) [Compound 52]

(a) Preparation of Compound 52:

Compound 11 (2.0 g, 4.65 mmol) was suspended in dry benzene (200 ml) and trifluoroacetic anhydride (2.59 ml, 18.60 mmol) was added. The resulting suspension, when stirred at room temperature, became pale yellow-brown solution in about 10 minutes. After one hour, the solvent was distilled off, and the residue was extracted with ethyl acetate. The organic layer was washed succesively with 1N.HCl, water, 4% NaHCO₃, and water and dried over magnesium sulfate. The solvent was evaporated and the residue was crystallized by adding isopropylether to give the compound 52 (1.67 g, yield, 91%) in white solid. m.p., 214°-215° C.

IR (KBr, cm⁻¹): 1760 (C=0)

¹ H-NMR (CDCl₃, δ): 8.33-7.20 (m, aromatic hydrogen, vinyl hydrogen).

Alternatively, the use of oxalyl chloride-DMF, DCC-DMAP or 2-chloro-N-methylpyridinium iodide --N(C₂ H₅)₃ in place of trifluoroacetic anhydride in this reaction also gave the compound 52.

(b) Preparation of Compound 51:

To the solution of dry CH₃ OH (0.15 ml, 3.81 mmol) in dry benzene (15 ml), n-butyl lithium (1.678M n-hexane solution) (1.66 ml, 2.79 mmol) was slowly added dropwise under ice cooling. After the addition, the solution was stirred at room temperature for 15 minutes. To the resulting solution of LiOCH₃, the compound 52 (500 mg, 1.27 mmol) obtained as above was added, and the mixture was heated under reflux for 30 minutes. After the reaction, the solvent was removed, and the residue was dissolved in chloroform, which was acidified (pH 2) by adding 1N.HCl under ice cooling. The organic layer was separated, washed with 1N.HCl and saturated brine and dried over magnesium sulfate. The solvent was evaporated. The viscous residue was dissolved in chloroform, and purified by silica gel column chromatography (developing solvent: benzene:ether=9:1). The third eluent was collected, from which the solvent was removed, and the residue was crystallized from isopropyl ether to give the desired pale yellow solid (411 mg, yield, 70%). m.p., 110°-111° C.

The IR and NMR spectra of the solid fully agreed with those of the product in Example 18.

The use of NaOCH₃ (28% methanol solution) in place of LiOCH₃ in this reaction also gave the desired compound.

EXAMPLE 20 Preparation of Compound 51 from dimethyl 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoate

Benzaldehyde (430 mg, 4.05 mmol) and dimethyl 2,2'-[(1,3-dioxo-1,3-propanediyl)diimino]bisbenzoate (1.0 g, 2.70 mmol) were heated under reflux in dry pyridine (8 ml) for 24 hours. After the reaction, pyridine was removed under reduced pressure from the reaction mixture, and the residue was treated with water (20 ml) to make it acidic with 10% HCl under ice cooling. The resulting solution was extracted with chloroform, organic layer was separated, washed with water and dried over magnesium sulfate. The solvent was evaporated under reduced pressure to give a yellow-brown oil. The oil was dissolved in the developing solvent and purified by silica gel column chromatography (developing solvent, benzene:ether=97:3) to give an oil, which was crystallized from n-hexane to give the desired compound of white solid (657 mg, yield, 53%). m.p., 110°-111° C.

IR and ¹ H-NMR spectra of the product fully agreed with those of the dimethyl ester obtained in Example 18.

EXAMPLE 21 Preparation of diisopropyl 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 53)

(a) The compound 11 (1.0 g, 2.3 mmol) was dissolved in dry acetone (25 ml) and dry DMF (5 ml) and K₂ CO₃ (639 mg, 4.6 mmol) and then isopropyl iodide (980 mg, 5.8 mmol) were added. By adding dry DMF (15 ml), the precipitated solid was dissolved, and the mixture was stirred at 60° C. for 5 hours. After completion of the reaction, the reaction solution was poured into ice water (500 ml) and extracted with ethyl acetate. After drying over magnesium sulfate and solvent-removal, the residue was dissolved in chloroform and purified by silica gel column chromatography [developing solvent: benzene:ether=9:1] to give the desired compound as pale yellow solid. Recrystallization from the mixed solution of methanol water yielded a white crystal (788 mg, yield, 67%). m.p., 132°-134° C.

IR (KBr, cm⁻¹): 3250, 3200, 1680.

¹ H-NMR (CDCl₃, δ): 12.00 (S, 1H, --CONH--), 11.47 (S, 1H, --CONH--), 8.95-6.95 (m, --CH═C--, aromatic hydrogen), 5.18 (septetx2, 2H, --CH(CH₃)₂ ×2), 1.33 (d, 6H, --CH(CH₃)₂), 1.23 (d, 6H, --CH(CH₃)₂).

(b) The compound 11 (4.0 g, 9.3 mmol) was suspended in dry benzene (100 ml) and (COCl)₂ (3.2 ml, 37.2 mmol) was dropwise added under ice cooling. To the mixture, 8 drops of dry DMF was further added, and the mixture was stirred at room temperature for 2 hours. After completion of the reaction, the solvent was removed, and the residue was extracted with chloroform. The extract was washed with 1N.HCl, saturated aqueous NaCl solution, 4% NaHCO₃ aqueous solution, and saturated aqueous NaCl solution and dried over MgSO₄. The solvent was evaporated to give a pale yellow solid. The resultant product was dissolved in a mixed solution of benzene:ethyl acetate=1:1 and applied on a silica gel column for chromatography (developing solvent, benzene:ethyl acetate-1:1). After removing the solvent from the eluent containing 2,2'-phenylethenilidene-bis(3,1-benzoxazine-4-one) [Compound 52], the residue was crystallized from isopropyl ether to give the Compound 52 in white solid (3.0 g, yield, 82%), which was recrystallized from the mixed solvent of benzene and n-hexane to give white crystal (2.5 g, yield, 68%). m.p., 214°-215° C.

IR (KBr, cm¹), 3450, 1760, 1655.

¹ H-NMR (CDCl₃, δ); 8.33-7.20 (aromatic hydrogen).

Then, to a solution of dry isopropanol (0.29 ml, 3.80 mmol) in dry benzene (10 ml), n-butyl lithium (1.678 M, n-hexane solution) (2.12 ml, 3.6 mmol) was gradually added dropwise under ice cooling. After stirring the reaction mixture at room temperature for 10 minutes, the solvent was removed to give LiOCH(CH₃)₂ in white solid, which was dissolved in dry benzene (15 ml). The above compound 52 (500 mg, 1.3 mmol) was added to the above solution and the mixture was refluxed for 30 minutes. After completion of the reaction, the solvent was removed, and the residue was dissolved in water and made weak acidic with 1N.HCl under ice cooling. After stirring the mixture for a while under ice cooling, the precipitated solid was collected on filter, washed with water, and dried. The solid was dissolved in chloroform and applied on a column for chromatography (developing solvent: benzene:ethyl acetate=4:1) to give the desired compound in white solid.

Recrystallization of the product from a mixed solvent of methanol and water gave white crystals (310 mg, yield, 47%).

The m.p., IR, and NMR spectra of the product fully agreed with those obtained in (a) above.

EXAMPLE 22 Preparation of di-tertiary butyl 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 54)

The compound 52 (1.0 g, 2.5 mmol) obtained in the same manner as in Example 21 (b) was dissolved in dry benzene (80 ml), treated with KOC(CH₃)₃ (684 mg, 6.1 mmol), and heated under reflux for 1 hour. After completion of the reaction, the solvent was evaporated and the residue was dried and suspended by adding a small amount of water under ice cooling. The aqueous layer was made neutral with 0.5N.HCl, and the residue was dissolved by adding chloroform. The mixed layer was removed to a separating funnel. After the solid was completely dissolved, water was added to wash the solution so as to make the chloroform layer neutral or weak acidic. The chloroform layer was separated, washed with saturated aqueous NaCl solution and dried over magnesium sulfate. The solvent was evaporated to give a white solid. The product was dissolved in chloroform and purified by silica gel column chromatography (developing solvent: benzene:ethyl acetate=4:1) to give the desired compound as white solid (801 mg, crude yield 58%). Recrystallization from the mixed solvent of methanol and water gave white crystals (654 mg, yield, 47%). m.p., 117°-118° C.

IR (KBr, cm⁻¹): 3250, 1680.

¹ H-NMR (CDCl₃, δ): 12.03 (S, 1H, --CONH--).11.57 (S, 1H, --CONH--), 9.0-7.0 (m, --CH═C-- aromatic hydrogen), 1.48 (S, 9H, --OC(CH₃)₃), 1.38 (S, 9H, --OC(CH₃)₃).

EXAMPLE 23 Preparation of di[2-(3-phthalidvlidene)ethyl]- -2,2'-[(1,3-dioxo-2-phenvlmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 55)

The compound 11 (1.0 g, 2.3 mmol) and dry N(C₂ H₅)₃ (0.64 ml, 4.6 mmol) were stirred in dry acetone (15 ml) at room temperature for 30 minutes. To the mixture, (Z)-3-(2-bromoethylidene)phthalide (1.1 g, 4.6 mmol) dissolved in dry acetone (10 ml) was added dropwise. After the addition, the mixture was stirred at room temperature for 72 hours. After the reaction, the precipitate was removed, and acetone was removed from the filtrate. The residue was extracted by chloroform, washed with aqueous solution of 4% NaHCO₃ (twice) and saturated NaCl aqueous solution (twice) and dried over magnesium sulfate. The solvent was evaporated to give a colorless viscous product. The obtained product was dissolved in the developing solvent and applied on a column for chromatography (developing solvent: benzene:ethyl acetate=4:1) to separate the desired product. Removal of solvent from the eluent gave a viscous substance, but cooling it with dry ice and acetone gave a white solid. Recrystallization from the mixed solvent of methanol and acetone gave white crystals (1.21 g, yield, 70%). m.p., 143°-146° C.

IR (KBr, cm⁻¹): 3250, 1790, 1685.

¹ H-NMR (CDCl₃, δ): 11.83 (S, 1H, --CONH--), 11.30 (S, 1H, --CONH--), 8.90-6.92 (m, CH═C--, aromatic hydrogen), 5.83 (tt, 2H, --CH₂ CH═phthalidylidene×2), 5.20 (d, 2H, --CH₂ CH=phthalidylidene), 4.93 (d, 2H, --CH₂ CH=phthalidylidene).

EXAMPLE 24 Preparation of di(3-phthalidyl)-2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 56)

The compound 11 (2.0 g, 4.7 mmol) and dry triethylamine (845 mg, 8.4 mmol) were stirred in acetone (23 ml) at room temperature for 30 minutes. To the mixture 3-bromophthalide (1.79 g, 8.4 mmol) dissolved in dry acetone (6 ml) was added, and the mixture was stirred at room temperature for 17 hours. After completion of the reaction, the precipitate was removed, and the solvent was removed from the filtrate. The residue was extracted with chloroform, washed with saturated NaHCO₃ aqueous solution and saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated to give a colorless viscous product. The product was dissolved in the developing solvent and applied on a silica gel column for chromatography (developing solvent: benzene:ether=9:1) to give the desired product of viscous substance.

Crystallization with isopropylether gave white solid (1.98 g, yield, 61%). As this substance shows a slight tendency of decomposition in the stage of separation and purification to produce impurities, it is difficult to obtain pure product. m.p., 131°-134° C. (methanol - THF).

IR (KBr, cm⁻¹): 3290, 1790, 1710, 1690.

¹ H-NMR (CDCl₃, δ): 11.73 (S, 1H, --CONH--), 11.13 (S, 1H, --CONH--), 9.00-6.87 (m, CH═C--, aromatic hydrogen, phthalidyl).

EXAMPLE 25 Preparation of di(pivaloyloxymethyl)- 2,2'-[(1,3-dioxo -2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 57)

The compound 11 (1.0 g, 2.3 mmol) and dry N(C₂ H₅)₃ (470 mg, 4.6 mmol) were stirred in dry acetone (17 ml) at room temperature for 30 minutes. To the mixture chloromethyl pivalate (721 mg, 4.6 mmol) and NaI (696 mg, 4.6 mmol) were added, and the mixture was heated under reflux for 6 hours.

After the reaction, the precipitate was removed, and the filtrate was evaporated. The residue was extracted with chloroform, washed with saturated aqueous NaHCO₃ solution and saturated aqueous NaCl solution, dried over anhydrous Na₂ SO₄ and the solvent was removed to give a viscous solid. The resulting product was dissolved in benzene and purified by silica gel column chromatography (developing solvent: isopropyl ether) to give the desired compound as white solid (1.23 g, 80%).

Recrystallization from the solution of mixture of benzene and n-hexane gave white crystals (1.04 g, 68%). m.p., 103°-104° C.

IR (KBr, cm⁻¹): 3275, 1750, 1705, 1685.

¹ H-NMR (CDCl₃, δ): 11.73 (S, 1H, --CONH--), 11.10 (S, 1H, --CONH--, 8.97-6.92 (m, CH=C, aromatic hydrogen), 5.95 (S, 2H, --OCH₂ OCO--), 5.68 (S, 2H, -OCH₂ OCO--), 1.19 (S, 9H, --C(CH₃)₃), 1.15 (S, 9H, --C(CH₃)₃).

EXAMPLE 26 Preparation of di[1-(ethoxycarbonyloxy)ethyl]-2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 58)

The compound 11 (2.0 g, 4.7 mmol) and dry N(C₂ H₅)₃ (1.13 g, 11.2 mmol) were stirred in dry acetone (60 ml) at room temperature for 30 minutes. The mixture was treated with ethyl 1-chloroethyl carbonate (1.70 g, 11.2 mmol) and NaI (1.67 g, 11.2 mmol) and heated under reflux for 23 hours. After completion of the reaction, the precipitate was removed, and the solvent was removed from the filtrate. The residue was extracted with benzene, washed with saturated aqueous solution of NaHCO₃ and saturated solution of NaCl and dried over anhydrous Na₂ SO₄. The solvent was evaporated to give a colorless viscous product. The resultant product was dissolved in developing solvent and purified by silica gel column chromatography (developing solvent: benzene:ether=95:5) to give the desired compound as white solid (1.34 g, crude yield, 44%). The solid was dissolved in methanol at room temperature, treated with water, and cooled with a solution of dry ice in acetone. The precipitated solid was filtered by suction, followed immediately by drying under reduced pressure to give the desired compound as white crystal (970 mg, yield, 32%). m.p., 48°-51° C.

IR (KBr, cm⁻¹): 3350, 1760, 1685.

¹ H-NMR (CDCl₃, δ): 11.73 (S, 1H, --CONH--), 11.13 (S, 1H, --CONH--), 8.90-6.46 (m, aromatic hydrogen, CH═C, --OCH(CH₃ O, 4.36-3.93 (q, 4H, --CH₂ CH₃ ×2), 1.70-1.10 (m, 12H, --CH(CH₃) ×2, --CH₂ CH₃ ×2).

EXAMPLE 27 Preparation of di[(5-methyl-2-oxo-1,3-dioxole-4yl)methyl]-2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoate (Compound 59) (Preparation of starting compound)

4,5-Dimethyl-1,3-dioxole-2-one (2.0 g, 17.5 mmol), N-bromosuccinimide (3.12 g, 17.5 mmol), and 2,2'-azobisisobutylonitrile (30 mg) were refluxed for 30 minutes in carbon tetrachloride (80 ml). After the reaction, the reaction solution was concentrated to half the volume, the precipitated solid was filtered off, and the solvent was removed from the filtrate. The residue was purified by column chromatography (developing solvent: benzene:ethyl acetate=8:2) to give yellow liquid (3.79 g). The resulting product was analyzed by gas chromatography and the area under the peak which was presumed to be 4-bromomethyl-5-methyl-1,3-dioxole-2-one [hereinafter to be referred to as Compound 59a] was roughly calculated to be approximately 70%. Accordingly, the content of Compound 59a in the above liquid was 2.65 g, yield, 78%. The product was used as such without purification.

[The Compound 59a is a known compound listed in Liebigs Ann. Chem. 1977, pages 27-32.]

(Preparation of desired compound)

The compound 11 (2.93 g, 6.85 mmol) and dry phthalidylidene (1.88 ml, 13.7 mmol) were stirred in dry acetone (60 ml) for 30 minutes to make a solution, into which was dropwise added the mixture obtained as above (3.79 g), which contained Compound 59a was 2.65 g, 13.7 mmol, dissolved in dry acetone (10 ml). After refluxing for 17 hours, the reaction solution was filtered to remove precipitate, the filtrate was concentrated, and the residue was extracted with chloroform (200 ml). The extract solution was washed with aqueous solution of NaHCO₃ (twice) and saturated aqueous solution of NaCl (twice) and dried over magnesium sulfate. The solvent was evaporated. The resulting yellow oily product was separated by column chromatography to give the desired compound (2.165 g, yield, 48%). (developing solvent: benzene:ether=9:1). The resulting white solid was recrystallized from methanol-THF-water to give white crystals (2.02 g). (Total yield from 4,5-dimethyl-1,3-dioxole-2-one was 35%.) m.p., 187°-189° C.

IR (KBr, cm⁻¹): 3310, 1825, 1740, 1690.

¹ H-NMR (CDCl₃, δ): 11.67 (S, 1H, CONH), 11.12 (S, 1H, --CONH--, 8.95-7.00 (m, aromatic hydrogen), 5.07 (S, 2H, --CH₂ --), 4.81 (S, 2H, --CH₂ --), 2.16 (S, 3H, --CH₃), 2.08 (S, 3H, --CH₃).

EXAMPLE 28 Preparation of high melting point form of 2,2'-[(1,3-dioxo-2-phenylmethylene-1,3-propanediyl)diimino]bisbenzoic acid [Compound 11]

The low melting point form of Compound 11 (0.1 g) was charged into a mortar and crushed with a pestle. By this treatment, the low melting point form was changed into the high melting point form of the following properties:

Melting point: 247°-249° C.

IR and NMR: Same as those of low melting point form.

The differential thermal analysis curves of the above low melting point form and high melting point form are shown in FIG. 5 and FIG. 6.

EXAMPLE 29 Preparation of high melting point form of

2,2'-[(1,3-dioxo-2-(2-thienyl)methylene-1,3-propanediyl)diimino]bisbenzoic acid [Compound 40]

The low melting point form of Compound 40 was treated in the same manner as in Example 28 to obtain the high melting point form having the following properties:

Melting point: 243°-245° C.

IR and NMR: Same as those of low melting point form.

The differential thermal analysis curves of the above low melting point form and high melting point form are shown in FIG. 7 and FIG. 8.

EXAMPLE 30 Preparation of high melting point form of 2,2'-[(1,3-dioxo-2-(3-thienyl)methylene-1,3-propanediyl)diimino]bisbenzoic acid [Compound 41]

The low melting point form of Compound 41 was trerated in the same manner as in Example 28 to obtain the high melting point form having the following properties:

Melting point: 245°-251° C.

IR and NMR: Same as those of low melting point form.

The differential thermal analysis curves of the above low melting point form and high melting point form are shown in FIG. 9 and FIG. 10.

EXAMPLE 31 Preparation of high melting point form of 2,2'-[(1,3-dioxo-2-(1-methyl-1H-pyrrol-2-yl)methylene-1,3-propanediyl)diimino]bisbenzoic acid [Compound 43]

The low melting point form of compound 43 was treated in the same manner as in Example 28 to obtain the high melting point form having the following properties:

Melting point: 236°-241° C.

IR and NMR: Same as those of the low melting point one.

The differential thermal analysis curves of the above low melting point form and the high melting point form compounds are shown in FIG. 11 and FIG. 12.

EXAMPLE 32 Preparation of 2,2'-phenylethenilidenbis(3,1-benzoxazine-4-one)(Compound 52)

The Compound 11 (4 g, 9.28 mmol) was suspended in dry benzene (100 ml) and oxalyl chloride (3.2 ml, 37.18 mmol) was added dropwise under ice cooling. Then, with addition of 8 drops of dry DMF, the mixture was stirred at room temperature for 2 hours. After the reaction, the solvent was removed and the residue was extracted with chloroform. The organic layer was washed with 1N.HCl, saturated brine, 4% NaHCO₃ aqueous solution, and saturated brine and dried over magnesium sulfate. The solvent was evaporated. The residue was dissolved in chloroform and applied on silica gel column for chromatography (benzene ethyl acetate=4:1). Recrystallization from isopropyl ether gave the desired compound 52 in crystal (3.26 g, yield, 89%). m.p., IR, and NMR spectra of the product fully agreed with those of the one obtained in Example 19.

EXAMPLE 33 Preparation of 2,2'-phenylethenilidenebis(3,1-benzoxazine-4-one)(Compound 52)

Under nitrogen gas current, 2-chloro-N-methylpyridinium iodide (691 mg, 2.78 mmol) was suspensed in dry methylene chloride (5 ml) and a solution of Compound 11 (500 mg, 1.16 mmol) and dry triethylamine (0.76 ml, 5.57 mmol) in dry methylene chloride (5 ml) were added. The mixture was stirred at 40° C. for 3.5 hours. After the reaction, methylene chloride was added, and the mixture was washed with 1N.HCl, water, 4% NaHCO₃ aqueous solution and water and dried over magnesium sulfate. The solvent was evaporated. The residue was crystallized from isopropylether to give the desired compound 52 in crystal (410 mg, yield, 90%). m.p., IR, and NMR spectra of the product fully agreed with those of the one obtained in Example 19.

EXAMPLE 34 Preparation of 2,2'-phenylethenilidenbis(3,1-benzoxazin-4-on)(Compound 52)

The Compound 11 (500 mg, 1.16 mmol) and 4dimethylaminopyridine (28 mg, 0.23 mmol) were suspended in dry methylene chloride (10 ml) and dicyclohexylcarbodiimide (605 mg, 2.78 mmol) was added under ice cooling. The mixture was stirred at 40° C. for 3.5 hours. After the reaction, the insoluble matter was filtered off, and methylene chloride was added to the filtrate, which was washed with 1N.HCl, water, 4% aqueous solution of NaHCO₃ and water and dried over magnesium sulfate. The solvent was evaporated. The residue was crystallized from isopropyl ether to give the desired compound 52 in crystal (415 mg, yield, 91%). m.p., IR, NMR spectra of the product fully agreed with those of the one obtained in Example 19.

Alternatively, by the reaction as in Example 32 using thionyl chloride in place of oxalyl chloride in benzene at room temperature for 2 hours, or using phosphorus oxychloride in benzene at 80° C. for 2 hours, or as in Example 36 using N,N'-carbonyldiimidazole in place of dicyclohexylcarbodiimide in tetrahydrofuran at room temperature for 2 hours, the desired compound 52 could also be obtained in a high yield.

EXAMPLE 35 Preparation of 2,2'-phenylethenilidenbis(3,1-benzoxazine-4-one)(Compound 52)

Benzaldehyde (259 mg, 2.45 mmol), Compound (2,2'-methylenebis(3,1-benzoxazine-4-one) (500 mg, 1.63 mmol), and BF₃.(C₂ H₅)₂ O (0.045 ml, 0.163 mmol) were heated under reflux in dry toluene (20 ml) for 20 hours. After the reaction, the solvent was removed under reduced pressure from the reaction mixture, the residue was treated with water, extracted with benzene, and the organic layer was separated, washed with water and dried over magnesium sulfate. The solvent was evaporated under reduced pressure. The residue was dissolved in the developing solvent and adsorbed on silica gel, and was purified by column chromatography to give the desired compound 52. The obtained product was crystallized from isopropylether to give the desired compound 52 in white solid in a good yield. m.p., IR, and NMR spectra of the product fully agreed with those of the one obtained in Example 19.

EXAMPLE 36 Preparation of 2,2'-[1,3-Dioxo-2-phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid dipotassium salt

Potassium carbonate (321 mg, 2.32 mmol) was dissolved in water (5 ml). The solution was heated to 80° C., treated with the Compound 11 (1.0 g, 2.32 mmol), and strirred for 3 hours. After cooling, the reaction mixture was sucked on a filter, and the solvent was removed from the filtrate. The residue was treated with acetone and crystallized to give the desired potassium salt in white solid (1.165 g, yield, 99.1%). m.p., 240°-245° C.

IR (KBr, cm⁻¹): 3400 (broad), 1685, 1490.

¹ H-NMR (DMSO-d₆, δ): 6.92-8.73 (m, 14H, aromatic hydrogen, vinyl hydrogen), 14.77 (brs, 1H, --CONH--), 15.22 (brs, 1H, --CONH--).

EXAMPLE 37 Preparation of 2,2'-[[1,3-dioxo-2-phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid calcium salt

The Compound 11 (430 mg 1 mmol) was treated with THF (20 ml) and water (10 ml), and further with calcium carbonate (100 mg, 1 mmol), and the mixture was stirred at room temperature for 24 hours. The reaction mixture was filtered by suction, and the solvent was removed from the filtrate. The residue was washed with acetone to give the desired calcium salt in pale yellow solid (420 mg, yield, 89.6%). m.p., 300° C. or higher.

IR (KBr, cm⁻¹); 3400 (broad), 1650, 1585, 1490.

¹ H-NMR (DMSO-d₆): 6.80-8.78 (m, 14H, aromatic hydrogen, vinyl hydrogen), 13.72 (brs, 1H, --CONH--), 14.37 (brs, 1H, --CONH).

EXAMPLE 38 Preparation of 2,2'-[[1,3-dioxo-2-phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid di(L-lvsine) salt

The Compound 11 (500 mg, 1.20 mmol) was dissolved in THF (5 ml), and L-lysine (351 mg, 2.40 mmol) dissolved in water (3 ml) was added.

The mixture was stirred at room temperature for 1 hour, after which the solvent was removed under reduced pressure. The residue was treated with THF and stirred for 1 hour to crystallize. The crystals were filtered and dried to give a pale yellow solid (780 mg.) The resulting solid was dissolved in water, and after filtering off the insoluble matter, water was removed under reduced pressure. The residue was crystallized from ether to give the desired compound as pale yellow solid (630 mg, yield, 74%). m.p., 176°-181° C.

IR (KBr, cm⁻¹); 3700-2200, 1580.

¹ H-NMR (DMSO-d₆, δ): 14.45 (s, 1H, --CONH--), 14.05 (s, 1H, --CONH--), 8.03-6.87 (m, aromatic hydrogen, vinyl hydrogen), 3.35 (br), 2.67 (br), 1.47 (br).

EXAMPLE 39 Preparation of 2,2'-[[1,3-dioxo-2-phenylmethylene-1,3-propanediyl]diimino]bisbenzoic acid di(L-arginine) salt

The Compound 11 (500 mg, 1.20 mmol) was dissolved in THF (5 ml), and L-arginine (418 mg, 2.40 mmol) dissolved in water (3 ml) was added. After stirring the mixture at room temperatrure for 1 hour, solvent was removed under reduced pressure. The residue was treated with THF and stirred for 1 hour to crystallize.

The crystals were filtered and dried to give a pale yellow solid (828 mg). The resulting solid was dissolved in water, and after filtering off the insoluble matter, water was removed under reduced pressure. The residue was crystallized from ether to give the desired compound as pale yellow solid (650 mg, yield, 71%). m.p., 191°-195° C.

IR (KBr, cm⁻¹): 3700-2200, 1580, 1620 (br).

¹ H-NMR (DMSO-d₆, δ): 14.38 (s, 1H, --CONH--), 13.93 (s, 1H, --CONH--, 8.67-6.87 (m, aromatic hydrogen, vinyl hydrogen), 3.35 (br), 3.07 (br), 1.68 (br).

EXAMPLE 40

    ______________________________________                                         (1)    Active ingredient      25.00  mg                                        (2)    Lactose                49.00  mg                                               Crystalline cellulose  36.00  mg                                               Corn starch            5.00   mg                                        (3)    Hydroxypropyl cellulose                                                                               1.00   mg                                        (4)    ECG505 (carboxymethyl cellulose                                                                       2.00   mg                                               calcium)                                                                (5)    Magnesium stearate     1.00   mg                                        (6)    Talc                   1.00   mg                                               Total                  120    mg                                        ______________________________________                                    

(1)+(2) were kneaded with 5% aqueous solution of (3), dried, and granulated, to which (4), (5), and (6) were added to mix together. The mixture was pressed into tablets of 120 mg each, 7 mm in diameter.

    ______________________________________                                         (1)    Active ingredient    50.00   mg                                         (2)    Lactose              124.50  mg                                         (3)    Corn starch          20.00   mg                                         (4)    Hydroxypropyl cellulose                                                                             2.00    mg                                         (5)    Light anhydrous silicic acid                                                                        1.50    mg                                         (6)    Magnesium stearate   2.00    mg                                                Total                200     mg                                         ______________________________________                                    

(1)+(2)+(3) were kneaded with 5% aqueous solution of (4), dried, and granulated, to which (5) and (6) were added to mix together, and the mixture was filled in No. 3 hard capsules at the rate of 200 mg per capsule.

(In the above Examples 40 and 41, the term active ingredient means optional one of the compounds of the formula (I').)

TEST EXAMPLE 1 Anti-hyaluronidase activity

It is known that, from the fact that disodium cromoglicate (DSCG), tranilast, etc. which are the anti-allergic agents inhibit hyaluronidase activity and the compound 48/80 and polymixin B which release histamine from the mast cell activate hyaluronidase, the hyaluronidase inhibiting activity can be made the index of the anti-allergic action. [The 5th Medicinal Chemistry Symposium (Dec. 9 and 10, 1983, in Kyoto) Synopsis of Lectures, page 68]. As a result of the tests for the anti-hyaluronidase activity on the compounds according to the present invention, they have been found to have the excellent activities.

(Test Method)

A buffer solution of hyaluronidase (0.1 ml) was taken in a test tube and 0.2 ml each of the buffer solution of various compounds in various concentrations was added, and the mixture was preincubated at 37° C. for 20 minutes. Then, an activating agent (Compound 48/80 or CaCl₂) (0.2 ml) was added to make the total amount 0.5 ml, which was incubated at 37° C. for 20 minutes. Then, potassium hyaluronate buffer solution (0.5 ml) was added, and the mixture was incubated at 37° C. for 40 minutes. After cooling, the mixture was treated with aqueous solution of 0.4N NaOH (0.2 ml) and neutralized to stop the reaction. The resulting product was subjected to measurement of OD₅₈₅ by the modified Morgan-Elson Method. As the control, buffer solution or water (0.2 ml) instead of various compounds was subjected to the similar operations and OD₅₈₅ was determined. (The final concentration of hyaluronidase was 340NF unit/ml.) ##EQU1##

(Results)

    ______________________________________                                         Compound                                                                               IC.sub.50 (mM)   Compound  IC.sub.50 (mM)                              ______________________________________                                         01      0.077            31        0.025                                       02      0.900 (IC.sub.20)                                                                               32        0.025                                       04      0.015 (IC.sub.10)                                                                               33        0.015                                       05      1.320 (IC.sub.10)                                                                               34        0.025                                       06      0.013            35        0.015                                       07      0.660 (IC.sub.10), 0.720 (IC.sub.20)                                                            36        0.025                                       08      0.220 (IC.sub.10)                                                                               37        0.017                                       09      0.134            38        0.023                                       11      0.022            39        0.040                                       12      0.065            40        0.035                                       13      0.055            41        0.060                                       15      0.055            42        0.025                                       16      0.010            43        0.040                                       17      0.142            44        0.073                                       18      0.290 (IC.sub.10)                                                                               45        0.010                                       19      0.013            46        0.030                                       20      0.040            49        0.035                                       21      0.015            50        0.050                                       22      0.008                                                                  23      0.030                                                                  24      0.020                                                                  25      0.013                                                                  26      0.020                                                                  27      0.030                                                                  28      0.110                                                                  29      0.020                                                                  30      0.010                                                                  ______________________________________                                    

As shown in the table, all the tested compounds were found to have strong hyaluronidase activity inhibiting actions.

TEST EXAMPLE 2 Anti-passive cutaneous anaphylaxis (PCA) activity in rats (Test method)

Wistar strain rats were sensitized with ovalbumin using aluminium hydroxide gel and Bordetella Pertussis vaccine as adjuvants. Dilutions of antiserum (16-fold and 32-fold) obtained by collecting blood samples 14 days later were administered subcutaneously in the dorsal skin of the rats of the same strain at the rate of 0.1 ml per spot, and the rats were grown for 48 hours. One hour after peroral administration of the sample solution, a mixture of antigen ovalbumin and Evans-blue dye was administered to the tail venous of the animal according to the ordinary procedure. Thirty minutes later, the animals were sacrificed by exsanguination, and the areas of blue spots (long diameter×short diameter) eliciting on the portion of the antiserum injection at the dorsal skin were measured to obtain the rate of inhibition based on the average value shown by the control animals.

(Results)

    ______________________________________                                         Anti-PCA activity                                                                     Dose mg/kg Average Inhibition Rate (%)                                           Route of admin.                                                                             Antiserum  Antiserum                                     Compound (N)          Dilution: x16                                                                             Dilution: x32                                 ______________________________________                                         Control  --     PO     10   0        0                                         Tranilast                                                                               200    PO     10   1.8      15.8                                      DSCG     100    PO     10   0.1      0.3                                       11       10     PO     10   23.2     33.1                                               50     PO     10   41.4     39.1                                               100    PO     10   52.9     53.5                                      06       10     PO     10   8.5      11.2                                               50     PO     10   14.9     13.3                                               100    PO     10   18.6     18.8                                      16       50     PO     10   3.2      9.0                                                100    PO     10   11.8     12.2                                      22       50     PO     10   19.7     22.6                                               100    PO     10   34.6     40.0                                      26       50     PO     10   8.3      10.0                                               100    PO     10   16.4     19.1                                      29       100    PO     10   3.4      3.9                                       30       10     PO     10   18.8     23.2                                               50     PO     10   23.4     33.3                                               100    PO     10   36.5     42.5                                      14       10     PO     10   38.6     38.7                                               50     PO     10   41.9     72.2                                               100    PO     10   59.3     85.1                                      52       10     PO     10   20.6     29.4                                               50     PO     10   37.9     38.3                                               100    PO     10   45.0     47.1                                      ______________________________________                                    

As shown in the above table, all the compounds were found to show anti-PCA activity by peroral administration. The control disodium cromoglicate showed no activity by peroral administration.

TEST EXAMPLE 3 Effect on reaction of passive sensitized guinea pig to inhalated antigen (Test method)

The compound 11 was compared with Tranilast and disodium cromoglicate in the experimental asthma models.

(1) Preparation of sample solution

The test compound and Tranilast were respectively suspended at the time of use in 5% gum arabic solution containing 0.1% Tween 80 at the rate of 40 mg/ml, and were perorally administered at the rate of 0.5 ml per 100 g body weight of the animal.

DSCG was dissolved at the time of use in physiological saline solultion for injection at the rate of 5.0 mg/ml, and was intravenously injected at the rate of 0.1 ml per 100 g body weight of the animal.

(2) Antigen inhalation test on passive sensitized guinea pig

Anti-ovalbumin rabbit serum diluted with physiological saline solution for injection so as to contain anti-ovalbumin rabbit antibody at the rate of 0.187 mg N/ml was intravenously administered to guinea pig at the rate of 0.1 ml per 100 g of body weight and it was passively sensitized.

Twenty-four hours later, the suspension of the compound prepared in (1) above was perorally or intravenously administered to the animal. The animal was put in the inhalation chamber one hour after the administration in case of the peroral administration and five minutes after the administration in case of the intravenous administration, and 2% physiological saline solution of antigen ovalbumin was inhaled by spraying. Over 10 minutes' period from the time immediately after the forced inhalation, the time until its fall attributed to anaphylaxis reaction was recorded, and the numbers of alive and dead animals after lapse of 10 minutes were also counted.

(Results)

    __________________________________________________________________________              Required time (sec.)                                                                              Average time                                                                            Extended                                  Com-                                                                               Dose for falling and    for falling                                                                             rate                                      pound                                                                              mg/kg N                                                                             Number of death (#)                                                                               Mean ± S.E.                                                                          (%)                                       __________________________________________________________________________              #  #  #  #                                                            Con-                                                                                -- po 5                                                                            123                                                                               139                                                                               152                                                                               160  203  155.4 ± 13.4                                    trol                                                                                    #                                                                     11  200 po 5                                                                            194                                                                               227                                                                               248                                                                                600<                                                                                600<                                                                               223.0 ± 15.7*                                                                        43.5                                               #  #  #  #    #                                                       trani-                                                                             200 po 5                                                                            116                                                                               126                                                                               141                                                                               181  190  150.8 ± 14.8 NS                                                                      -3.0                                      last                                                                                    #     #                                                               DSCG                                                                                5 iv 5                                                                             142                                                                               188                                                                               199                                                                               241   600<                                                                               192.5 ± 20.3 NS                                                                      23.9                                      __________________________________________________________________________

As shown in Table, Compound 11 showed a strong preventive effect on anaphylaxis reaction to the experimental asthma models, well surpassing the action of 5 mg/kg sodium cromoglicate for venous injection, while Tranilast showed no activity in the present test method.

TEST EXAMPLE 4 Study on Anti-ulcer activity in experimental ulcer model (Shay)

Study was made on the anti-ulcer activity of the test compound.

(Animals used)

Using 5 eight-week old Wistar strain male rats of 1 group, the rats were previously fasted for 4.8 hours. The compound of an amount proportionate to the body weight based on the body weight after fasting was administered intraduodenally or intraperitoneally.

(Preparation of sample solution)

Each test compound was evenly suspended or dissolved in an aqueous solution of 0.5% CMC containing 0.1% Tween 80, and administered at the rate of 0.5 ml per 100 g of body weight of the animal. To the controls, only the solvent was administered.

(Test method)

Test was carried out in accordance with Shay's method. After 48 hours' fasting, 5 animals per group were subjected to laparotomy under ether anesthesia, the tract between pylorus of stomach and duodenum was ligated, and the solution of the compound was administered intraduodenally (id) or intraperitoneally (ip), followed by suturing the laparotomy part. Eight hours after administration of the compound liquid, each animal was sacrificed by ether anesthesia and stomach was removed. Then, evaluation on the ulcer condition on the inner surface of stomach, and determination of the amount of gastric juice, of acidity by alkali titration, and of pepsin titer based on substrate of hemoglovin were made on the stored gastric juice. With regard to the acidity, gastric juice amount, and pepsin titer, the results were shown in inhibition rate (%) based on the average value of the control groups.

(Results)

As shown in the Table, the compound used showed excellent results in ulcer index and inhibition of gastric acid, of secretion amount of gastric juice, and of total pepsin titer.

    __________________________________________________________________________     Anti-ulcer activity in experimental ulcer model (Shay)                         (n = 5)                                                                                                    Inhibition %                                                                  Gastric secretion total                                                            amount of                                                 Dose Ulcer Index *1  gastric                                                                              pepsin                                    Compound                                                                             Route                                                                              (mg/kg)                                                                             0 1 2 3 4 5 Acidity                                                                            juice titer                                     __________________________________________________________________________     Control                                                                              id  --   0 0 1 3 1 0 0   0     0                                         Ranitidine                                                                           id   30  1 4 0 0 0 0 63.0                                                                               25.2  20.6                                      11    id  100  0 0 3 2 0 0 4.7 0     0                                               id  200  0 1 2 2 0 0 16.5                                                                               20.1  9.1                                       20    id  100  1 3 1 0 0 0 64.5                                                                               28.1  42.5                                            id  200  2 2 1 0 0 0 99.5                                                                               59.0  69.3                                            ip   10  1 3 1 0 0 0 52.3                                                                               26.3  31.4                                            ip   50  4 1 0 0 0 0 88.0                                                                               70.9  60.7                                      23    id  100  0 0 2 2 1 0 32.5                                                                               8.5   31.1                                            id  200  0 2 3 0 0 0 40.2                                                                               11.2  41.2                                      25    id  100  0 0 1 3 1 0 45.2                                                                               25.5  32.1                                            id  200  0 1 2 2 0 0 80.0                                                                               50.7  40.5                                            ip   50  2 1 2 0 0 0 67.4                                                                               53.4  82.2                                      29    id  100  0 0 0 4 1 0 0   0     0                                               id  200  0 0 0 3 2 0 0.7 0.5   0                                         22    id  100  0 0 1 3 1 0 9.1 11.1  7.2                                             id  200  0 0 1 3 1 0 13.2                                                                               11.6  10.1                                            id  300  0 0 0 4 1 0 15.7                                                                               24.9  8.3                                             ip   50  0 2 2 1 0 0 38.2                                                                               29.0  37.2                                      __________________________________________________________________________      *1: Ulcer index of Adami                                                 

TEST EXAMPLE 5 Anti-SRS-A activity (Method of preparing crude SRS-A solution)

A piece of lungs of guinea pig sensitized with ovalbumin was incubated with antigen ovalbumin at 37° C. for 20 minutes to obtain a supernatant solution, which was used as a crude SRS-A solution.

(Determination of anti-SRS-A reaction)

A piece of ileum of normal guinea pig was suspended in Magnus tube filled with Tyrode's solution and incubated with the solution of drug to be examined for a certain duration, and the contraction of the piece of ileum induced by adding the above crude SRS-A solution was determined on the basis of the contraction rate attributed to hystamine dihydrochloride 10⁻⁶ M. The rate of inhibition against the contraction amount was taken as anti-SRS-A activity.

(Result)

    ______________________________________                                         Anti-SRS-A activity                                                            Compound   10.sup.-6                                                                             10.sup.-5 10.sup.-4                                                                           10.sup.-3                                                                             (M)                                    ______________________________________                                         Tranilast  0      0         0    0                                             11         0      0         0    31.8                                          ______________________________________                                    

The test compound 11 showed a moderate anti-SRS-A activity at a concentration of 10⁻³ M. To the contrary, no activity was noticed with Tranilast which was used as control.

TEST EXAMPLE 6 Activity of inhibition of histamine release from mast cell in abdominal cavity in rat

Examination was made on the activity of inhibition of histamine release from mast cell by antigen-antibody reaction.

(Preparing of DNP-Ascaris anti-serum)

Swine ascaris extract solution was dinitrophenylated according to Aisen's method, dialysed, and lyophilized. The product was administered as antigen together with Bordetella Pertussis vaccine subcutaneously into the foot pad of rat. Eight days later, blood was taken to obtain antiserum. The PCA titer for this antiserum in rat was 32 to 64.

(Method of collecting mast cell in abdominal cavity and sensitizing cell)

Heparin-containing PBS was injected intraperitoneally to rat which was sacrificed by exsanguination, after which the abdomen was well massaged to collect the injected PBS, which was purified by washing several times by centrifugation. The number of the mast cells contained in the solution was determined and adjusted to the designed concentration. As to method of sensitizing the cell, the above cell suspension (6 ml, 2×10⁶ cells/ml) was treated with anti-DNP-Ascaris rat serum (PCA titer 32) (6 ml) and the mixture was incubated in the presence of heparin at 37° C. for 2 hours.

(Quantitative determination of released histamine)

To the sensitized mast cell suspension the solution of the drug to be tested was added, and the mixture was preliminarily incubated at 37° C. for 12 minutes. After addition of the solution of antigen DNP-Ascaris (final concentration, 20 microgramms/ml), the mixture was further incubated for 20 minutes. After completion of the reaction, the solution was centrifuged (500 G, 10 min.) under a low temperature to obtain a supernatant solution. Histamine contained in the supernatant solution was subjected to fluorometry by orthophthalaldehyde method.

(Results)

Amount of histamine released from peritoneal mast cell (Control=100):

    ______________________________________                                         Compound   10.sup.-6                                                                             10.sup.-5 10.sup.-4                                                                           10.sup.-3                                                                             (M)                                    ______________________________________                                         Tranilast  95     95        67   29                                            11         55     51        59   13                                            52         70     68        60   21                                            ______________________________________                                    

Final concentration of DNP-Ascaris (antigen): 20 microgramms/ml

The compound 11 and 52 showed the action of inhibiting release of histamine from the mast cell even at the low concentration of 10⁻⁶ M. It showed the stronger inhibitory activity than the control Tranilast in the range of 10⁻⁶ M to 10⁻³ M.

TEST EXAMPLE 7 Preventive activity against passive systemic anaphylaxis (PSA) in quinea pig

Effect of the compound on prevention of death by passive systemic anaphylaxis was examined in guinea pig.

(Method)

Normal Hartley strain female guinea pig (body weight, 240-260 g) was sensitized by intravenous administration of anti-ovalbumin rabbit serum. It was perorally administered with the compound 11 in the amount of 200 mg/kg. One hour later, it was intravenously administered with 2% physiological saline solution of antigen ovalbumin at the rate of 0.05 ml. Thereafter, the state was observed, and the time (seconds) until death was measured. Similar treatments were given to the control group animals, to which physiological saline instead of the Compound 11 was perorally administered in the same procedure.

(Results)

As shown in Table, the average living time of the group of animals administered with Compound 11 was 441.7 seconds while that of the control group was 294.9 seconds. Thus, the Compound 11 was found to have statistically significant anti-PSA activity.

    __________________________________________________________________________                              Ave. time                                             Com- Dose Required time (sec.)                                                                          to death                                                                               Extended                                      pound                                                                               mg/kg N                                                                             to death       Mean ± S.E.                                                                         rate (%)                                      __________________________________________________________________________     Control                                                                              -- po 10                                                                           236                                                                               245                                                                               302                                                                               237                                                                               312                                                                311                                                                               251                                                                               315                                                                               374                                                                               366                                                                               294.90 ± 16.2                                                                       --                                            11   200 po 10                                                                           431                                                                               548                                                                               488                                                                               475                                                                               367                                                                492                                                                               431                                                                               485                                                                               352                                                                               348                                                                               441.70 ± 21.5*                                                                      49.8                                          __________________________________________________________________________      Note:                                                                          *shows that p is less than 0.01.                                         

TEST EXAMPLE 8 Acute Toxicity

ddy-Strain mice (male) and Wistar strain rats were used to obtain LD₅₀ values

(Test method)

According to the ordinary procedure, suspension or solution of test sample was administered to the animals. From the number of the died animals until one week after the administration, LD₅₀ values were obtained by Probit method.

(Results)

    ______________________________________                                         LD.sub.50 value (mg/kg body weight)                                                       Mouse       Rat                                                     Compound     p.o.       i.v.   p.o.                                            ______________________________________                                         11           10000<     343.8  10000<                                          20           10000<     224.9  10000<                                          24           10000<     274.8  --                                              30            8381      257.7  --                                              14           10000<     299.1  --                                              ______________________________________                                    

As shown in Table, the LD₅₀ values of the compounds were more than 10,000 mg/kg in peroral administration, and more than 200 mg/kg in intravenous administration in mouse. Accordingly, these compounds were found to be the substances having extremely low toxicity.

TEST EXAMPLE 9 Anti-passive cutaneous anaphylaxis activitY (PCA) in rats

This test was conducted in a manner similar to that in Test Example 2, except that the dilutions of antiserum were 12- and 24-folds.

(Results)

    ______________________________________                                                           Number                                                                Dose     of       Anti-serum                                                                              Anti-serum                                 Compound (mg/kg)  example  Dilution: x12                                                                           Dilution: x24                              ______________________________________                                         Control           10       0    (%)   0    (%)                                 Tranilast                                                                               200      10       2.1        10.7                                     DSCG     100      10       0          0                                        Compound 11                                                                             50       10       20.8       23.0                                     51       10       10       28.1       30.3                                              50       10       34.2       37.5                                     14       10       10       29.8       31.3                                              50       10       36.7       40.5                                     53       50       10       26.1       23.9                                     54       10       10       33.0       34.3                                              50       10       38.8       42.6                                     57       10       10       37.0       30.9                                              50       10       45.0       50.1                                     59       10       10       22.0       25.1                                              50       10       65.7       62.0                                     56       10       10       44.7       43.6                                              50       10       49.7       58.4                                     58       10       10       40.2       43.1                                              50       10       50.8       57.6                                     ______________________________________                                    

From the above results it was found that the compounds according to the present invention had the extremely stronger anti-PCA activity than Tranilast and DSCG, and their anti-PCA activity were stronger than that of the compound 11.

TEST EXAMPLE 10 Activity of inhibition of release of histamine from mast cell in abdominal cavity of rat

Examination was made on the activity of inhibition of histamine release from mast cell by antigen-antibody reaction.

Preparation of DNP-Ascaris antiserum was conducted in a manner similar to that in Test Example 6.

(Methods of collecting mast cell in abdominal cavity and thoracic cavity and of sensitizing cell)

Heparin-containing PBS was injected into the abdominal cavity of rat which was sacrificed by bleeding, after which the abdomen was well massaged, and then peritoneal exudate was sampled. The same liquid was also injected into the thoracic cavity, and after shaking the breast for several minutes, the thoracic cavity liquid was sampled, which was purified by washing several times by centrifugation. The number of the mast cells contained in this liquid was measured and adjusted to a designated concentration (Mast cells, 8.0×10⁴ cells/ml).

To the cell suspension (4 ml, 9×10⁵ cells/ml), anti-DNP-Ascaris rat serum (PCA titer, 32) (4 ml) was added, and the mixture was incubated in the presence of heparin at 37° C. for 2.5 hours. To the solution, 70 microgramms/ml phosphatidylserin PBS solution (0.5 ml) was added and the mixture was incubated at 37° C. for 12 minutes, after which 140 microgramms/ml antigen DNP-Ascaris PBS solution (0.5 ml) was added and the mixture was incubated further for 20 minutes.

(Method of histamin assay)

After completion of the reaction, the reaction liquid was centrifuged (500 G, 10 min.) to obtain supernatant solution, and histamin in the supernatant solution was subjected to fluorometry by orthophthalal aldehyde method. The released amount of histamin in the control was shown as 100.

(Result)

    ______________________________________                                                 Mast cell in abdominal                                                                      Mast cell in thoracic                                             cavity 10.sup.-3 M                                                                          cavity 10.sup.-3 M                                        ______________________________________                                         Compound 51                                                                              50.4           75.1                                                  DSCG      76.8           104.8                                                 ______________________________________                                    

From the above results it was found that the compound 51 showed an action of inhibiting release of histamine from the mast cells in abdominal acvity and thoracic cavity at a concentration of 10⁻³ M, this activity having been stronger than DSCG.

TEST EXAMPLE 11 Acute Toxicity (Test method)

As test animals, ICR-strain mice (male) were used. According to the conventional procedure, suspension or solution of test sample was administered to the animals. From the number of the died animals until one week after the administration, LD₅₀ values were obtained by Provit method.

(Results)

    ______________________________________                                                     LD.sub.50 Value                                                                (mg/kg of body weight)                                                           Peroral    Intravenous                                           Compound      administration                                                                            administration                                        ______________________________________                                         Compound 51   8000 & above                                                                              238                                                   14                       347                                                   54                       312                                                   52            >10000     319                                                   ______________________________________                                    

From the above results it was known that the esters other than methyl ester had the lower toxicity than the methyl ester (known compound).

TEST EXAMPLE 12 Actvity of inhibiting release of histamine from the mast cells in abdominal cavity and thoracic cavity of rat

Collection of mast cells in abdominal cavity and thoracic cavity and sensitizing of cells were conducted in similar manners to those in Test Example 10, respectively.

(Histamine releasing substance) (1) In the case of dextran (T-500)

The sample solution was treated with 105 microgramms/ml phosphatidylserin PBS solution (0.5 ml) and incubated at 37° C. for 30 minutes, followed by addition of 25 mg/ml dextran (T-500) PBS solution (0.5 ml) and further incubation for 15 minutes.

(2) In the case of antigen DNP-Ascaris

(1) Preparation of DNP-Ascaris antiserum was conducted in manner similar to that in Test Example 6.

(2) Method of sensitizing cells and release of histamine:

This is conducted in a manner similar to that in Test Example 10.

(Quantitative determination method of histamin)

This is conducted in a manner similar to that in Test Example 10.

(Results) (1) Effect on release of histamine by dextran (T-500)

    ______________________________________                                                 Mast cell in abdominal                                                                       Mast cell in thoracic                                            cavity        cavity                                                           10.sup.-4 M                                                                           10.sup.-3 M                                                                               10.sup.-4                                                                               10.sup.-3 M                                 ______________________________________                                         Compound 14                                                                              94.5     40.2       55.6   42.2                                      DSCG      52.9     60.0       42.2   42.2                                      ______________________________________                                    

(2) Effect on release of histamine by antigen DNP-Ascaris

    ______________________________________                                                 Mast cell in abdominal                                                                      Mast cell in thoracic                                             cavity 10.sup.-3 M                                                                          cavity 10.sup.-3 M                                        ______________________________________                                         Compound 21                                                                              48.3           73.0                                                  DSCG      76.8           104.8                                                 ______________________________________                                    

From the above results it was seen that (1) the compound of the compound 14 showed the histamine release inhibiting activities at 10⁻⁴ and 10⁻³ M and its activity was almost the same as that of DSCG, and (2) the compound 14 showed a histamine release inhibiting activity at 10⁻³ M, with the stronger inhibiting activity than DSCG.

From the above, it was shown that the compounds of the present invention had the anti-allergy action and immunomodulating action. 

What is claimed is:
 1. A compound of the general formula: ##STR59## wherein A and B are both hydrogen, or one of A and B is a group (G) of the formula: ##STR60## and the other is a group R⁵, wherein R¹ is an aryl group or a substituted aryl group wherein the substituent is halogen, hydroxy, C₁₋₆ lower alkoxy, C₁₋₆ lower alkylenedioxy, halo (C₁₋₆) lower alkyl, cyano, nitro, mono- or di-(C₁₋₆) alkylamino or C₁₋₆ lower alkanoylamino; or a 5-membered or 6-membered C₁₋₆ alkyl substituted or unsubstituted heterocyclic group containing a heteroatom selected from oxygen, nitrogen and sulfur, or a condensed heterocyclic group consisting of a heterocycle as defined above and a benzene nucleus, and R⁴ and R⁵ are both hydrogeh or together form a single chemical bond, R² and R² ' are independently hydrogen, halogen, nitro, (C₁₋₆) lower alkyl or (C₁₋₆) lower alkoxy, and R³ and R³ ' are independently carboxy or its functional derivative, with the proviso that(a) when A and B are both hydrogen, then R² and R² ' cannot be hydrogen or (C₁₋₆) lower alkyl, and (b) when one A and B is the group (G) and the other is the group R⁵ wherein R⁴ and R⁵ together form a single chemical bond, R¹ is unsubstituted aryl and R² and R² ' are independently hydrogen or C₁₋₆ lower alkyl, then R³ and R³ ' are independently carboxy or its functional derivative other than methyl ester, and, where applicable, pharmaceutically acceptable salts thereof.
 2. The compound of claim 1, wherein one of A and B is the group (G) and the other is the group R⁵.
 3. The compound of claim 2, wherein R⁴ and R⁵ together form a single chemical bond.
 4. The compound of claim 3, which is represented by the general formula: ##STR61## wherein R is a residue derived from an alcohol having two or more carbon atoms by removing hydroxy group.
 5. The compound of claim 3, which is the higher melting point form of the compound of the general formula: ##STR62## wherein R¹ is phenyl, 2-thienyl, 3-thienyl or 1-methyl-2-pyrrolyl. 